linux_old1/drivers/acpi/ec.c

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/*
* ec.c - ACPI Embedded Controller Driver (v2.1)
*
* Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
* Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
* Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
/* Uncomment next line to get verbose printout */
/* #define DEBUG */
#define pr_fmt(fmt) "ACPI : EC: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/spinlock.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
ACPI: Clean up inclusions of ACPI header files Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h> inclusions and remove some inclusions of those files that aren't necessary. First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h> should not be included directly from any files that are built for CONFIG_ACPI unset, because that generally leads to build warnings about undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set, <linux/acpi.h> includes those files and for CONFIG_ACPI unset it provides stub ACPI symbols to be used in that case. Second, there are ordering dependencies between those files that always have to be met. Namely, it is required that <acpi/acpi_bus.h> be included prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the latter depends on are always there. And <acpi/acpi.h> which provides basic ACPICA type declarations should always be included prior to any other ACPI headers in CONFIG_ACPI builds. That also is taken care of including <linux/acpi.h> as appropriate. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Tony Luck <tony.luck@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff) Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-12-03 08:49:16 +08:00
#include <linux/acpi.h>
#include <linux/dmi.h>
ACPI: Clean up inclusions of ACPI header files Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h> inclusions and remove some inclusions of those files that aren't necessary. First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h> should not be included directly from any files that are built for CONFIG_ACPI unset, because that generally leads to build warnings about undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set, <linux/acpi.h> includes those files and for CONFIG_ACPI unset it provides stub ACPI symbols to be used in that case. Second, there are ordering dependencies between those files that always have to be met. Namely, it is required that <acpi/acpi_bus.h> be included prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the latter depends on are always there. And <acpi/acpi.h> which provides basic ACPICA type declarations should always be included prior to any other ACPI headers in CONFIG_ACPI builds. That also is taken care of including <linux/acpi.h> as appropriate. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Tony Luck <tony.luck@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff) Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-12-03 08:49:16 +08:00
#include <asm/io.h>
#include "internal.h"
#define ACPI_EC_CLASS "embedded_controller"
#define ACPI_EC_DEVICE_NAME "Embedded Controller"
#define ACPI_EC_FILE_INFO "info"
/* EC status register */
#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
/* EC commands */
enum ec_command {
ACPI_EC_COMMAND_READ = 0x80,
ACPI_EC_COMMAND_WRITE = 0x81,
ACPI_EC_BURST_ENABLE = 0x82,
ACPI_EC_BURST_DISABLE = 0x83,
ACPI_EC_COMMAND_QUERY = 0x84,
};
#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
#define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
* when trying to clear the EC */
enum {
EC_FLAGS_QUERY_PENDING, /* Query is pending */
EC_FLAGS_GPE_STORM, /* GPE storm detected */
EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and
* OpReg are installed */
EC_FLAGS_BLOCKED, /* Transactions are blocked */
};
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
module_param(ec_delay, uint, 0644);
MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
/*
* If the number of false interrupts per one transaction exceeds
* this threshold, will think there is a GPE storm happened and
* will disable the GPE for normal transaction.
*/
static unsigned int ec_storm_threshold __read_mostly = 8;
module_param(ec_storm_threshold, uint, 0644);
MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
struct acpi_ec_query_handler {
struct list_head node;
acpi_ec_query_func func;
acpi_handle handle;
void *data;
u8 query_bit;
};
struct transaction {
const u8 *wdata;
u8 *rdata;
unsigned short irq_count;
u8 command;
u8 wi;
u8 ri;
u8 wlen;
u8 rlen;
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
u8 flags;
};
struct acpi_ec *boot_ec, *first_ec;
EXPORT_SYMBOL(first_ec);
static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
/* --------------------------------------------------------------------------
Transaction Management
-------------------------------------------------------------------------- */
static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
{
u8 x = inb(ec->command_addr);
pr_debug("---> status = 0x%2.2x\n", x);
return x;
}
static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
{
u8 x = inb(ec->data_addr);
pr_debug("---> data = 0x%2.2x\n", x);
return x;
}
static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
{
pr_debug("<--- command = 0x%2.2x\n", command);
outb(command, ec->command_addr);
}
static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
{
pr_debug("<--- data = 0x%2.2x\n", data);
outb(data, ec->data_addr);
}
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
static int ec_transaction_completed(struct acpi_ec *ec)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&ec->lock, flags);
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
if (!ec->curr || (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
ret = 1;
spin_unlock_irqrestore(&ec->lock, flags);
return ret;
}
ACPI / EC: Avoid race condition related to advance_transaction() The advance_transaction() will be invoked from the IRQ context GPE handler and the task context ec_poll(). The handling of this function is locked so that the EC state machine are ensured to be advanced sequentially. But there is a problem. Before invoking advance_transaction(), EC_SC(R) is read. Then for advance_transaction(), there could be race condition around the lock from both contexts. The first one reading the register could fail this race and when it passes the stale register value to the state machine advancement code, the hardware condition is totally different from when the register is read. And the hardware accesses determined from the wrong hardware status can break the EC state machine. And there could be cases that the functionalities of the platform firmware are seriously affected. For example: 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the hardware will either refuse to respond a next EC_SC(W) write of the next command or discard the current WR_EC command when it receives a EC_SC(W) write of the next command. 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write. The next EC_DATA(R) could never be responded by the hardware. This is the root cause of the reported issue. Fix this issue by moving the EC_SC(R) access into the lock so that we can ensure that the state machine is advanced consistently. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:17 +08:00
static void advance_transaction(struct acpi_ec *ec)
{
struct transaction *t;
ACPI / EC: Avoid race condition related to advance_transaction() The advance_transaction() will be invoked from the IRQ context GPE handler and the task context ec_poll(). The handling of this function is locked so that the EC state machine are ensured to be advanced sequentially. But there is a problem. Before invoking advance_transaction(), EC_SC(R) is read. Then for advance_transaction(), there could be race condition around the lock from both contexts. The first one reading the register could fail this race and when it passes the stale register value to the state machine advancement code, the hardware condition is totally different from when the register is read. And the hardware accesses determined from the wrong hardware status can break the EC state machine. And there could be cases that the functionalities of the platform firmware are seriously affected. For example: 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the hardware will either refuse to respond a next EC_SC(W) write of the next command or discard the current WR_EC command when it receives a EC_SC(W) write of the next command. 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write. The next EC_DATA(R) could never be responded by the hardware. This is the root cause of the reported issue. Fix this issue by moving the EC_SC(R) access into the lock so that we can ensure that the state machine is advanced consistently. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:17 +08:00
u8 status;
ACPI / EC: Avoid race condition related to advance_transaction() The advance_transaction() will be invoked from the IRQ context GPE handler and the task context ec_poll(). The handling of this function is locked so that the EC state machine are ensured to be advanced sequentially. But there is a problem. Before invoking advance_transaction(), EC_SC(R) is read. Then for advance_transaction(), there could be race condition around the lock from both contexts. The first one reading the register could fail this race and when it passes the stale register value to the state machine advancement code, the hardware condition is totally different from when the register is read. And the hardware accesses determined from the wrong hardware status can break the EC state machine. And there could be cases that the functionalities of the platform firmware are seriously affected. For example: 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the hardware will either refuse to respond a next EC_SC(W) write of the next command or discard the current WR_EC command when it receives a EC_SC(W) write of the next command. 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write. The next EC_DATA(R) could never be responded by the hardware. This is the root cause of the reported issue. Fix this issue by moving the EC_SC(R) access into the lock so that we can ensure that the state machine is advanced consistently. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:17 +08:00
pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
status = acpi_ec_read_status(ec);
t = ec->curr;
if (!t)
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
goto err;
if (t->flags & ACPI_EC_COMMAND_POLL) {
if (t->wlen > t->wi) {
if ((status & ACPI_EC_FLAG_IBF) == 0)
acpi_ec_write_data(ec, t->wdata[t->wi++]);
else
goto err;
} else if (t->rlen > t->ri) {
if ((status & ACPI_EC_FLAG_OBF) == 1) {
t->rdata[t->ri++] = acpi_ec_read_data(ec);
if (t->rlen == t->ri)
t->flags |= ACPI_EC_COMMAND_COMPLETE;
} else
goto err;
} else if (t->wlen == t->wi &&
(status & ACPI_EC_FLAG_IBF) == 0)
t->flags |= ACPI_EC_COMMAND_COMPLETE;
return;
} else {
if ((status & ACPI_EC_FLAG_IBF) == 0) {
acpi_ec_write_cmd(ec, t->command);
t->flags |= ACPI_EC_COMMAND_POLL;
} else
goto err;
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
return;
}
err:
/*
* If SCI bit is set, then don't think it's a false IRQ
* otherwise will take a not handled IRQ as a false one.
*/
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
if (!(status & ACPI_EC_FLAG_SCI)) {
if (in_interrupt() && t)
++t->irq_count;
}
}
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
static void start_transaction(struct acpi_ec *ec)
{
ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
ec->curr->flags = 0;
advance_transaction(ec);
}
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
{
if (state & ACPI_EC_FLAG_SCI) {
if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
return acpi_ec_sync_query(ec, NULL);
}
return 0;
}
static int ec_poll(struct acpi_ec *ec)
{
unsigned long flags;
int repeat = 5; /* number of command restarts */
while (repeat--) {
unsigned long delay = jiffies +
msecs_to_jiffies(ec_delay);
do {
/* don't sleep with disabled interrupts */
if (EC_FLAGS_MSI || irqs_disabled()) {
udelay(ACPI_EC_MSI_UDELAY);
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
if (ec_transaction_completed(ec))
return 0;
} else {
if (wait_event_timeout(ec->wait,
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
ec_transaction_completed(ec),
msecs_to_jiffies(1)))
return 0;
}
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
spin_lock_irqsave(&ec->lock, flags);
ACPI / EC: Avoid race condition related to advance_transaction() The advance_transaction() will be invoked from the IRQ context GPE handler and the task context ec_poll(). The handling of this function is locked so that the EC state machine are ensured to be advanced sequentially. But there is a problem. Before invoking advance_transaction(), EC_SC(R) is read. Then for advance_transaction(), there could be race condition around the lock from both contexts. The first one reading the register could fail this race and when it passes the stale register value to the state machine advancement code, the hardware condition is totally different from when the register is read. And the hardware accesses determined from the wrong hardware status can break the EC state machine. And there could be cases that the functionalities of the platform firmware are seriously affected. For example: 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the hardware will either refuse to respond a next EC_SC(W) write of the next command or discard the current WR_EC command when it receives a EC_SC(W) write of the next command. 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write. The next EC_DATA(R) could never be responded by the hardware. This is the root cause of the reported issue. Fix this issue by moving the EC_SC(R) access into the lock so that we can ensure that the state machine is advanced consistently. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:17 +08:00
advance_transaction(ec);
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
spin_unlock_irqrestore(&ec->lock, flags);
} while (time_before(jiffies, delay));
pr_debug("controller reset, restart transaction\n");
spin_lock_irqsave(&ec->lock, flags);
start_transaction(ec);
spin_unlock_irqrestore(&ec->lock, flags);
}
return -ETIME;
}
static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
struct transaction *t)
{
unsigned long tmp;
int ret = 0;
if (EC_FLAGS_MSI)
udelay(ACPI_EC_MSI_UDELAY);
/* start transaction */
spin_lock_irqsave(&ec->lock, tmp);
/* following two actions should be kept atomic */
ec->curr = t;
start_transaction(ec);
if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
spin_unlock_irqrestore(&ec->lock, tmp);
ret = ec_poll(ec);
spin_lock_irqsave(&ec->lock, tmp);
ec->curr = NULL;
spin_unlock_irqrestore(&ec->lock, tmp);
return ret;
}
static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
{
int status;
u32 glk;
if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
return -EINVAL;
if (t->rdata)
memset(t->rdata, 0, t->rlen);
mutex_lock(&ec->mutex);
if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
status = -EINVAL;
goto unlock;
}
if (ec->global_lock) {
status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
if (ACPI_FAILURE(status)) {
status = -ENODEV;
goto unlock;
}
}
pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
t->command, t->wdata ? t->wdata[0] : 0);
/* disable GPE during transaction if storm is detected */
if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
/* It has to be disabled, so that it doesn't trigger. */
acpi_disable_gpe(NULL, ec->gpe);
}
status = acpi_ec_transaction_unlocked(ec, t);
/* check if we received SCI during transaction */
ec_check_sci_sync(ec, acpi_ec_read_status(ec));
if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
msleep(1);
/* It is safe to enable the GPE outside of the transaction. */
acpi_enable_gpe(NULL, ec->gpe);
} else if (t->irq_count > ec_storm_threshold) {
pr_info("GPE storm detected(%d GPEs), "
"transactions will use polling mode\n",
t->irq_count);
set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
}
pr_debug("transaction end\n");
if (ec->global_lock)
acpi_release_global_lock(glk);
unlock:
mutex_unlock(&ec->mutex);
return status;
}
static int acpi_ec_burst_enable(struct acpi_ec *ec)
{
u8 d;
struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
.wdata = NULL, .rdata = &d,
.wlen = 0, .rlen = 1};
return acpi_ec_transaction(ec, &t);
}
static int acpi_ec_burst_disable(struct acpi_ec *ec)
{
struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
.wdata = NULL, .rdata = NULL,
.wlen = 0, .rlen = 0};
return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
acpi_ec_transaction(ec, &t) : 0;
}
static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
{
int result;
u8 d;
struct transaction t = {.command = ACPI_EC_COMMAND_READ,
.wdata = &address, .rdata = &d,
.wlen = 1, .rlen = 1};
result = acpi_ec_transaction(ec, &t);
*data = d;
return result;
}
static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
{
u8 wdata[2] = { address, data };
struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
.wdata = wdata, .rdata = NULL,
.wlen = 2, .rlen = 0};
return acpi_ec_transaction(ec, &t);
}
int ec_read(u8 addr, u8 *val)
{
int err;
u8 temp_data;
if (!first_ec)
return -ENODEV;
err = acpi_ec_read(first_ec, addr, &temp_data);
if (!err) {
*val = temp_data;
return 0;
} else
return err;
}
EXPORT_SYMBOL(ec_read);
int ec_write(u8 addr, u8 val)
{
int err;
if (!first_ec)
return -ENODEV;
err = acpi_ec_write(first_ec, addr, val);
return err;
}
EXPORT_SYMBOL(ec_write);
int ec_transaction(u8 command,
const u8 * wdata, unsigned wdata_len,
u8 * rdata, unsigned rdata_len)
{
struct transaction t = {.command = command,
.wdata = wdata, .rdata = rdata,
.wlen = wdata_len, .rlen = rdata_len};
if (!first_ec)
return -ENODEV;
return acpi_ec_transaction(first_ec, &t);
}
EXPORT_SYMBOL(ec_transaction);
/* Get the handle to the EC device */
acpi_handle ec_get_handle(void)
{
if (!first_ec)
return NULL;
return first_ec->handle;
}
EXPORT_SYMBOL(ec_get_handle);
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
/*
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
* Process _Q events that might have accumulated in the EC.
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
* Run with locked ec mutex.
*/
static void acpi_ec_clear(struct acpi_ec *ec)
{
int i, status;
u8 value = 0;
for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
status = acpi_ec_sync_query(ec, &value);
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
if (status || !value)
break;
}
if (unlikely(i == ACPI_EC_CLEAR_MAX))
pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
else
pr_info("%d stale EC events cleared\n", i);
}
void acpi_ec_block_transactions(void)
{
struct acpi_ec *ec = first_ec;
if (!ec)
return;
mutex_lock(&ec->mutex);
/* Prevent transactions from being carried out */
set_bit(EC_FLAGS_BLOCKED, &ec->flags);
mutex_unlock(&ec->mutex);
}
void acpi_ec_unblock_transactions(void)
{
struct acpi_ec *ec = first_ec;
if (!ec)
return;
mutex_lock(&ec->mutex);
/* Allow transactions to be carried out again */
clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
if (EC_FLAGS_CLEAR_ON_RESUME)
acpi_ec_clear(ec);
mutex_unlock(&ec->mutex);
}
void acpi_ec_unblock_transactions_early(void)
{
/*
* Allow transactions to happen again (this function is called from
* atomic context during wakeup, so we don't need to acquire the mutex).
*/
if (first_ec)
clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
}
static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
{
int result;
u8 d;
struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
.wdata = NULL, .rdata = &d,
.wlen = 0, .rlen = 1};
if (!ec || !data)
return -EINVAL;
/*
* Query the EC to find out which _Qxx method we need to evaluate.
* Note that successful completion of the query causes the ACPI_EC_SCI
* bit to be cleared (and thus clearing the interrupt source).
*/
result = acpi_ec_transaction_unlocked(ec, &t);
if (result)
return result;
if (!d)
return -ENODATA;
*data = d;
return 0;
}
/* --------------------------------------------------------------------------
Event Management
-------------------------------------------------------------------------- */
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
acpi_handle handle, acpi_ec_query_func func,
void *data)
{
struct acpi_ec_query_handler *handler =
kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
if (!handler)
return -ENOMEM;
handler->query_bit = query_bit;
handler->handle = handle;
handler->func = func;
handler->data = data;
mutex_lock(&ec->mutex);
list_add(&handler->node, &ec->list);
mutex_unlock(&ec->mutex);
return 0;
}
EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
{
struct acpi_ec_query_handler *handler, *tmp;
mutex_lock(&ec->mutex);
list_for_each_entry_safe(handler, tmp, &ec->list, node) {
if (query_bit == handler->query_bit) {
list_del(&handler->node);
kfree(handler);
}
}
mutex_unlock(&ec->mutex);
}
EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
static void acpi_ec_run(void *cxt)
{
struct acpi_ec_query_handler *handler = cxt;
if (!handler)
return;
pr_debug("start query execution\n");
if (handler->func)
handler->func(handler->data);
else if (handler->handle)
acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
pr_debug("stop query execution\n");
kfree(handler);
}
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
{
u8 value = 0;
int status;
struct acpi_ec_query_handler *handler, *copy;
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
status = acpi_ec_query_unlocked(ec, &value);
if (data)
*data = value;
if (status)
return status;
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
list_for_each_entry(handler, &ec->list, node) {
if (value == handler->query_bit) {
/* have custom handler for this bit */
copy = kmalloc(sizeof(*handler), GFP_KERNEL);
if (!copy)
return -ENOMEM;
memcpy(copy, handler, sizeof(*copy));
pr_debug("push query execution (0x%2x) on queue\n",
value);
return acpi_os_execute((copy->func) ?
OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
acpi_ec_run, copy);
}
}
return 0;
}
static void acpi_ec_gpe_query(void *ec_cxt)
{
struct acpi_ec *ec = ec_cxt;
if (!ec)
return;
mutex_lock(&ec->mutex);
ACPI / EC: Process rather than discard events in acpi_ec_clear Address a regression caused by commit ad332c8a4533: (ACPI / EC: Clear stale EC events on Samsung systems) After the earlier patch, there was found to be a race condition on some earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was sometimes discarding a new EC event before its GPE was triggered by the system. In the case of these systems, this meant that the "lid open" event was not registered on resume if that was the cause of the wake, leading to problems when attempting to close the lid to suspend again. After testing on a number of Samsung systems, both those affected by the previous EC bug and those affected by the race condition, it seemed that the best course of action was to process rather than discard the events. On Samsung systems which accumulate stale EC events, there does not seem to be any adverse side-effects of running the associated _Q methods. This patch adds an argument to the static function acpi_ec_sync_query so that it may be used within the acpi_ec_clear loop in place of acpi_ec_query_unlocked which was used previously. With thanks to Stefan Biereigel for reporting the issue, and for all the people who helped test the new patch on affected systems. Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems) References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-29 22:51:20 +08:00
acpi_ec_sync_query(ec, NULL);
mutex_unlock(&ec->mutex);
}
static int ec_check_sci(struct acpi_ec *ec, u8 state)
{
if (state & ACPI_EC_FLAG_SCI) {
if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
pr_debug("push gpe query to the queue\n");
return acpi_os_execute(OSL_NOTIFY_HANDLER,
acpi_ec_gpe_query, ec);
}
}
return 0;
}
static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
u32 gpe_number, void *data)
{
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
unsigned long flags;
struct acpi_ec *ec = data;
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
spin_lock_irqsave(&ec->lock, flags);
ACPI / EC: Avoid race condition related to advance_transaction() The advance_transaction() will be invoked from the IRQ context GPE handler and the task context ec_poll(). The handling of this function is locked so that the EC state machine are ensured to be advanced sequentially. But there is a problem. Before invoking advance_transaction(), EC_SC(R) is read. Then for advance_transaction(), there could be race condition around the lock from both contexts. The first one reading the register could fail this race and when it passes the stale register value to the state machine advancement code, the hardware condition is totally different from when the register is read. And the hardware accesses determined from the wrong hardware status can break the EC state machine. And there could be cases that the functionalities of the platform firmware are seriously affected. For example: 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the hardware will either refuse to respond a next EC_SC(W) write of the next command or discard the current WR_EC command when it receives a EC_SC(W) write of the next command. 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write. The next EC_DATA(R) could never be responded by the hardware. This is the root cause of the reported issue. Fix this issue by moving the EC_SC(R) access into the lock so that we can ensure that the state machine is advanced consistently. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:17 +08:00
advance_transaction(ec);
ACPI / EC: Add asynchronous command byte write support Move the first command byte write into advance_transaction() so that all EC register accesses that can affect the command processing state machine can happen in this asynchronous state machine advancement function. The advance_transaction() function then can be a complete implementation of an asyncrhonous transaction for a single command so that: 1. The first command byte can be written in the interrupt context; 2. The command completion waiter can also be used to wait the first command byte's timeout; 3. In BURST mode, the follow-up command bytes can be written in the interrupt context directly, so that it doesn't need to return to the task context. Returning to the task context reduces the throughput of the BURST mode and in the worst cases where the system workload is very high, this leads to the hardware driven automatic BURST mode exit. In order not to increase memory consumption, convert 'done' into 'flags' to contain multiple indications: 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition, indicating the completion of the command transaction. 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first command byte. A new command can utilize this flag to compete for the right of accessing the underlying hardware. There is a follow-up bug fix that has utilized this new flag. The 2 flags are important because it also reflects a key concept of IO programs' design used in the system softwares. Normally an IO program running in the kernel should first be implemented in the asynchronous way. And the 2 flags are the most common way to implement its synchronous operations on top of the asynchronous operations: 1. POLL: This flag can be used to block until the asynchronous operations can happen. 2. COMPLETE: This flag can be used to block until the asynchronous operations have completed. By constructing code cleanly in this way, many difficult problems can be solved smoothly. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-15 08:41:35 +08:00
spin_unlock_irqrestore(&ec->lock, flags);
if (ec_transaction_completed(ec)) {
wake_up(&ec->wait);
ec_check_sci(ec, acpi_ec_read_status(ec));
}
return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
}
/* --------------------------------------------------------------------------
Address Space Management
-------------------------------------------------------------------------- */
static acpi_status
acpi_ec_space_handler(u32 function, acpi_physical_address address,
u32 bits, u64 *value64,
void *handler_context, void *region_context)
{
struct acpi_ec *ec = handler_context;
int result = 0, i, bytes = bits / 8;
u8 *value = (u8 *)value64;
if ((address > 0xFF) || !value || !handler_context)
return AE_BAD_PARAMETER;
if (function != ACPI_READ && function != ACPI_WRITE)
return AE_BAD_PARAMETER;
if (EC_FLAGS_MSI || bits > 8)
acpi_ec_burst_enable(ec);
for (i = 0; i < bytes; ++i, ++address, ++value)
result = (function == ACPI_READ) ?
acpi_ec_read(ec, address, value) :
acpi_ec_write(ec, address, *value);
if (EC_FLAGS_MSI || bits > 8)
acpi_ec_burst_disable(ec);
switch (result) {
case -EINVAL:
return AE_BAD_PARAMETER;
break;
case -ENODEV:
return AE_NOT_FOUND;
break;
case -ETIME:
return AE_TIME;
break;
default:
return AE_OK;
}
}
/* --------------------------------------------------------------------------
Driver Interface
-------------------------------------------------------------------------- */
static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context);
static struct acpi_ec *make_acpi_ec(void)
{
struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
if (!ec)
return NULL;
ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
mutex_init(&ec->mutex);
init_waitqueue_head(&ec->wait);
INIT_LIST_HEAD(&ec->list);
spin_lock_init(&ec->lock);
return ec;
}
static acpi_status
acpi_ec_register_query_methods(acpi_handle handle, u32 level,
void *context, void **return_value)
{
char node_name[5];
struct acpi_buffer buffer = { sizeof(node_name), node_name };
struct acpi_ec *ec = context;
int value = 0;
acpi_status status;
status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
}
return AE_OK;
}
static acpi_status
ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
{
acpi_status status;
unsigned long long tmp = 0;
struct acpi_ec *ec = context;
/* clear addr values, ec_parse_io_ports depend on it */
ec->command_addr = ec->data_addr = 0;
status = acpi_walk_resources(handle, METHOD_NAME__CRS,
ec_parse_io_ports, ec);
if (ACPI_FAILURE(status))
return status;
/* Get GPE bit assignment (EC events). */
/* TODO: Add support for _GPE returning a package */
status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
if (ACPI_FAILURE(status))
return status;
ec->gpe = tmp;
/* Use the global lock for all EC transactions? */
tmp = 0;
acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
ec->global_lock = tmp;
ec->handle = handle;
return AE_CTRL_TERMINATE;
}
static int ec_install_handlers(struct acpi_ec *ec)
{
acpi_status status;
if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
return 0;
status = acpi_install_gpe_handler(NULL, ec->gpe,
ACPI_GPE_EDGE_TRIGGERED,
&acpi_ec_gpe_handler, ec);
if (ACPI_FAILURE(status))
return -ENODEV;
acpi_enable_gpe(NULL, ec->gpe);
status = acpi_install_address_space_handler(ec->handle,
ACPI_ADR_SPACE_EC,
&acpi_ec_space_handler,
NULL, ec);
if (ACPI_FAILURE(status)) {
if (status == AE_NOT_FOUND) {
/*
* Maybe OS fails in evaluating the _REG object.
* The AE_NOT_FOUND error will be ignored and OS
* continue to initialize EC.
*/
pr_err("Fail in evaluating the _REG object"
" of EC device. Broken bios is suspected.\n");
} else {
acpi_disable_gpe(NULL, ec->gpe);
acpi_remove_gpe_handler(NULL, ec->gpe,
&acpi_ec_gpe_handler);
return -ENODEV;
}
}
set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
return 0;
}
static void ec_remove_handlers(struct acpi_ec *ec)
{
acpi_disable_gpe(NULL, ec->gpe);
if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
pr_err("failed to remove space handler\n");
if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
&acpi_ec_gpe_handler)))
pr_err("failed to remove gpe handler\n");
clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
}
static int acpi_ec_add(struct acpi_device *device)
{
struct acpi_ec *ec = NULL;
int ret;
strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_EC_CLASS);
/* Check for boot EC */
if (boot_ec &&
(boot_ec->handle == device->handle ||
boot_ec->handle == ACPI_ROOT_OBJECT)) {
ec = boot_ec;
boot_ec = NULL;
} else {
ec = make_acpi_ec();
if (!ec)
return -ENOMEM;
}
if (ec_parse_device(device->handle, 0, ec, NULL) !=
AE_CTRL_TERMINATE) {
kfree(ec);
return -EINVAL;
}
/* Find and register all query methods */
acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
acpi_ec_register_query_methods, NULL, ec, NULL);
if (!first_ec)
first_ec = ec;
device->driver_data = ec;
ret = !!request_region(ec->data_addr, 1, "EC data");
WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
ret = !!request_region(ec->command_addr, 1, "EC cmd");
WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
ec->gpe, ec->command_addr, ec->data_addr);
ret = ec_install_handlers(ec);
/* EC is fully operational, allow queries */
clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
/* Clear stale _Q events if hardware might require that */
if (EC_FLAGS_CLEAR_ON_RESUME) {
mutex_lock(&ec->mutex);
acpi_ec_clear(ec);
mutex_unlock(&ec->mutex);
}
return ret;
}
static int acpi_ec_remove(struct acpi_device *device)
{
struct acpi_ec *ec;
struct acpi_ec_query_handler *handler, *tmp;
if (!device)
return -EINVAL;
ec = acpi_driver_data(device);
ec_remove_handlers(ec);
mutex_lock(&ec->mutex);
list_for_each_entry_safe(handler, tmp, &ec->list, node) {
list_del(&handler->node);
kfree(handler);
}
mutex_unlock(&ec->mutex);
release_region(ec->data_addr, 1);
release_region(ec->command_addr, 1);
device->driver_data = NULL;
if (ec == first_ec)
first_ec = NULL;
kfree(ec);
return 0;
}
static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context)
{
struct acpi_ec *ec = context;
if (resource->type != ACPI_RESOURCE_TYPE_IO)
return AE_OK;
/*
* The first address region returned is the data port, and
* the second address region returned is the status/command
* port.
*/
if (ec->data_addr == 0)
ec->data_addr = resource->data.io.minimum;
else if (ec->command_addr == 0)
ec->command_addr = resource->data.io.minimum;
else
return AE_CTRL_TERMINATE;
return AE_OK;
}
int __init acpi_boot_ec_enable(void)
{
if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
return 0;
if (!ec_install_handlers(boot_ec)) {
first_ec = boot_ec;
return 0;
}
return -EFAULT;
}
static const struct acpi_device_id ec_device_ids[] = {
{"PNP0C09", 0},
{"", 0},
};
/* Some BIOS do not survive early DSDT scan, skip it */
static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
{
EC_FLAGS_SKIP_DSDT_SCAN = 1;
return 0;
}
/* ASUStek often supplies us with broken ECDT, validate it */
static int ec_validate_ecdt(const struct dmi_system_id *id)
{
EC_FLAGS_VALIDATE_ECDT = 1;
return 0;
}
/* MSI EC needs special treatment, enable it */
static int ec_flag_msi(const struct dmi_system_id *id)
{
pr_debug("Detected MSI hardware, enabling workarounds.\n");
EC_FLAGS_MSI = 1;
EC_FLAGS_VALIDATE_ECDT = 1;
return 0;
}
/*
* Clevo M720 notebook actually works ok with IRQ mode, if we lifted
* the GPE storm threshold back to 20
*/
static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
{
pr_debug("Setting the EC GPE storm threshold to 20\n");
ec_storm_threshold = 20;
return 0;
}
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
/*
* On some hardware it is necessary to clear events accumulated by the EC during
* sleep. These ECs stop reporting GPEs until they are manually polled, if too
* many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
*
* https://bugzilla.kernel.org/show_bug.cgi?id=44161
*
* Ideally, the EC should also be instructed NOT to accumulate events during
* sleep (which Windows seems to do somehow), but the interface to control this
* behaviour is not known at this time.
*
* Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
* however it is very likely that other Samsung models are affected.
*
* On systems which don't accumulate _Q events during sleep, this extra check
* should be harmless.
*/
static int ec_clear_on_resume(const struct dmi_system_id *id)
{
pr_debug("Detected system needing EC poll on resume.\n");
EC_FLAGS_CLEAR_ON_RESUME = 1;
return 0;
}
static struct dmi_system_id ec_dmi_table[] __initdata = {
{
ec_skip_dsdt_scan, "Compal JFL92", {
DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
{
ec_flag_msi, "MSI hardware", {
DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
{
ec_flag_msi, "MSI hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
{
ec_flag_msi, "MSI hardware", {
DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
{
ec_flag_msi, "MSI hardware", {
DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
{
ec_flag_msi, "Quanta hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
{
ec_flag_msi, "Quanta hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
{
ec_validate_ecdt, "ASUS hardware", {
DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
{
ec_validate_ecdt, "ASUS hardware", {
DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
{
ec_enlarge_storm_threshold, "CLEVO hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
{
ec_skip_dsdt_scan, "HP Folio 13", {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
{
ec_validate_ecdt, "ASUS hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
ACPI / EC: Clear stale EC events on Samsung systems A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. The loop which clears the stale events is based on an earlier patch by Lan Tianyu (see referenced attachment). This patch: - Adds a function acpi_ec_clear() which polls the EC for stale _Q events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-28 22:12:28 +08:00
{
ec_clear_on_resume, "Samsung hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
{},
};
int __init acpi_ec_ecdt_probe(void)
{
acpi_status status;
struct acpi_ec *saved_ec = NULL;
struct acpi_table_ecdt *ecdt_ptr;
boot_ec = make_acpi_ec();
if (!boot_ec)
return -ENOMEM;
/*
* Generate a boot ec context
*/
dmi_check_system(ec_dmi_table);
status = acpi_get_table(ACPI_SIG_ECDT, 1,
(struct acpi_table_header **)&ecdt_ptr);
if (ACPI_SUCCESS(status)) {
pr_info("EC description table is found, configuring boot EC\n");
boot_ec->command_addr = ecdt_ptr->control.address;
boot_ec->data_addr = ecdt_ptr->data.address;
boot_ec->gpe = ecdt_ptr->gpe;
boot_ec->handle = ACPI_ROOT_OBJECT;
acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
/* Don't trust ECDT, which comes from ASUSTek */
if (!EC_FLAGS_VALIDATE_ECDT)
goto install;
saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
if (!saved_ec)
return -ENOMEM;
/* fall through */
}
if (EC_FLAGS_SKIP_DSDT_SCAN)
return -ENODEV;
/* This workaround is needed only on some broken machines,
* which require early EC, but fail to provide ECDT */
pr_debug("Look up EC in DSDT\n");
status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
boot_ec, NULL);
/* Check that acpi_get_devices actually find something */
if (ACPI_FAILURE(status) || !boot_ec->handle)
goto error;
if (saved_ec) {
/* try to find good ECDT from ASUSTek */
if (saved_ec->command_addr != boot_ec->command_addr ||
saved_ec->data_addr != boot_ec->data_addr ||
saved_ec->gpe != boot_ec->gpe ||
saved_ec->handle != boot_ec->handle)
pr_info("ASUSTek keeps feeding us with broken "
"ECDT tables, which are very hard to workaround. "
"Trying to use DSDT EC info instead. Please send "
"output of acpidump to linux-acpi@vger.kernel.org\n");
kfree(saved_ec);
saved_ec = NULL;
} else {
/* We really need to limit this workaround, the only ASUS,
* which needs it, has fake EC._INI method, so use it as flag.
* Keep boot_ec struct as it will be needed soon.
*/
if (!dmi_name_in_vendors("ASUS") ||
!acpi_has_method(boot_ec->handle, "_INI"))
return -ENODEV;
}
install:
if (!ec_install_handlers(boot_ec)) {
first_ec = boot_ec;
return 0;
}
error:
kfree(boot_ec);
boot_ec = NULL;
return -ENODEV;
}
static struct acpi_driver acpi_ec_driver = {
.name = "ec",
.class = ACPI_EC_CLASS,
.ids = ec_device_ids,
.ops = {
.add = acpi_ec_add,
.remove = acpi_ec_remove,
},
};
int __init acpi_ec_init(void)
{
int result = 0;
/* Now register the driver for the EC */
result = acpi_bus_register_driver(&acpi_ec_driver);
if (result < 0)
return -ENODEV;
return result;
}
/* EC driver currently not unloadable */
#if 0
static void __exit acpi_ec_exit(void)
{
acpi_bus_unregister_driver(&acpi_ec_driver);
return;
}
#endif /* 0 */