This change fixes a deadlock when the multiplexer is closed while there
are still client side ports open.
When the multiplexer is closed and there are active tty's it tries to
close them with tty_vhangup. This has a problem though, because
tty_vhangup needs the tty_lock. This patch changes it to unlock the
tty_lock before attempting the hangup and relocks afterwards. The
additional call to tty_port_tty_set is needed because otherwise the
port stays active because of the reference counter.
This change also exposed another problem that other code paths don't
expect that the multiplexer could have been closed. This patch also adds
checks for these cases in the gsmtty_ class of function that could be
called.
The documentation explicitly states that "first close all virtual ports
before closing the physical port" but we've found this to not always
reality in our field situations. The GPRS / UTMS modem sometimes crashes
and needs a power cycle in that case which means cleanly shutting down
everything is not always possible. This change makes it much more robust
for our situation where at least the system is recoverable with this patch
and doesn't hang in a deadlock situation inside the kernel.
The patch is against the long term support kernel (3.4.27) and should
apply cleanly to more recent branches. Tested with a Telit GE864-QUADV2
and Telit HE910 modem.
Signed-off-by: Dirkjan Bussink <dirkjan.bussink@nedap.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MIPS based Ralink WiSoC platform has 1 or more 8250 compatible serial cores.
To make them work we require the same quirks that are used by AU1x00.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dan Carpenter noticed a missing set of parentheses
around a multiple field addition.
https://lkml.org/lkml/2013/1/27/166
His original commit message:
There is a kind of precedence problem here, but it doesn't affect how
the code works because ->serial_signals is unsigned char. We want to
clear two flags here.
#define SerialSignal_RTS 0x20 /* Request to Send */
#define SerialSignal_DTR 0x80 /* Data Terminal Ready */
Without the parenthesis then it does:
info->serial_signals &= 0x5f;
With the parenthesis it does:
info->serial_signals &= 0xffffff5f;
info->serial_signals is an unsigned char so the two statements are
equivalent, but it's cleaner to add the parenthesis. In other dtr_rts()
functions the parenthesis are there so this makes it more consistent.
Other changes:
Convert all + uses to | for these bit operations.
Reorder the multiple fields for consistency.
Update the comments too.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for later SUNIX (TIMEDIA) Universal PCI Single and Multi-Port
Communications Boards.
These boards have PCI Vendor ID 1fd4 with device ID 1999 but otherwise
appear to be the same as the TIMEDIA boards already supported by 8250_pci
and parport_serial.
Tested with:
a. the two port serial board part number SER5037A,
b. the two port serial and one port parallel board part number
MIO5079A.
Signed-off-by: Stephen Chivers <schivers@csc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When PCH_UART_CONSOLE and SERIAL_CORE_CONSOLE is not set neither, the
uart_port will have no 'sysrq' member hence their will need a '#ifdef'
in pch_uart.c to handle the case, otherwise we'll see compile error
like this:
CC [M] drivers/tty/serial/pch_uart.o
drivers/tty/serial/pch_uart.c: In function 'pch_uart_hal_read':
drivers/tty/serial/pch_uart.c:572:11: error: 'struct uart_port' has no member named 'sysrq'
make[4]: *** [drivers/tty/serial/pch_uart.o] Error 1
Reported-by: Randy Dunlap <rdunlap@infradead.org>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Liang Li <liang.li@windriver.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the tty input buffer is full and thereby throttled,
flushing/resetting the read buffer should unthrottle to allow more
data to be received.
Signed-off-by: Karthik Manamcheri <Karthik.Manamcheri@ni.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sorry forgot to merge this in the original submission. Resync
with the tty tree changes moving the buffers into the tty_port
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.
devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__exit_p() need to be removed after the __devexit
removal from the driver.
Warning log:
drivers/tty/serial/xilinx_uartps.c:996:12:
warning: 'xuartps_remove' defined but not used [-Wunused-function]
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need to memset 0 to SPI frame memory before preparing
transfer frame bits, because SPI frame header are encoded with valid
data size, so don't need to worry about adopting dirty bits, more,
memset zero for each SPI frame may impact the spi throughput efficiency.
Signed-off-by: Chen Jun <jun.d.chen@intel.com>
Signed-off-by: channing <chao.bi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This provides a console driver for the Goldfish virtual platform. The original
is from Arve with changes from Jun Nakajima and Tom Keel. This has been then
been ported to the current kernel and to the tty port mechanism by Alan Cox.
In the process it gained proper POSIX semantics and vhangup works. The default
name is not ttyS as this belongs to the 8250 driver. Instead ttyGFx is now used.
In the normal usage case the first port serves as a kernel logging console and
the second one carries various other data streams for the emulation.
Signed-off-by: Arve Hjønnevåg <arve@google.com>
[Cleaned up to handle x86]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
[Moved to 3.7 and chunks rewritten to use tty_port layer]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This struct is used only for driver, so it should be static.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a hardware reset the break and overflow bits for
these events. Without resetting the bits they will be reported to
the core every time, when once occur.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The non-dt probing allowed passing the location via platform data from
the beginning. So make up leeway for device tree probing.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for specifying clock information for the uart clk via the
device tree. This eliminates the need to hardcode rates in the device
tree.
Signed-off-by: Josh Cartwright <josh.cartwright@ni.com>
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When send break to the uart port, we always get 'frame error', but we
can not just reset receive fifo in such case, otherwise the sysrq cmd
will not be received correctly.
When we handle sysrq output via pch_console_write, the priv lock has
already been taken so no need to take the lock in pch_console_write.
Signed-off-by: Liang Li <liang.li@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we use pch_uart as system console like 'console=ttyPCH0,115200',
then 'send break' to it. We'll encounter the deadlock on a cpu/core,
with interrupts disabled on the core. When we happen to have all irqs
affinity to cpu0 then the deadlock on cpu0 actually deadlock whole
system.
In pch_uart_interrupt, we have spin_lock_irqsave(&priv->lock, flags)
then call pch_uart_err_ir when break is received. Then the call to
dev_err would actually call to pch_console_write then we'll run into
another spin_lock(&priv->lock), with interrupts disabled.
So in the call sequence lead by pch_uart_interrupt, we should be
carefully to call functions that will 'print message to console' only
in case the uart port is not being used as serial console.
Signed-off-by: Liang Li <liang.li@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The root of problem is carelessly zeroing pointer(in function __tty_buffer_flush()),
when another thread can use it. It can be cause of "NULL pointer dereference".
Main idea of the patch, this is never free last (struct tty_buffer) in the active buffer.
Only flush the data for ldisc(buf->head->read = buf->head->commit).
At that moment driver can collect(write) data in buffer without conflict.
It is repeat behavior of flush_to_ldisc(), only without feeding data to ldisc.
Also revert:
commit c56a00a165
tty: hold lock across tty buffer finding and buffer filling
In order to delete the unneeded locks any more.
Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fields must be null-terminated, or next printk for %s, will cause issue.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.
The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer. Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.
bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY. The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.
add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function old new delta
chr_dev_init 166 170 +4
allow_signal 80 82 +2
static.__warned 143 142 -1
disallow_signal 63 62 -1
__set_special_pids 95 94 -1
unregister_console 126 121 -5
start_kernel 546 541 -5
register_console 593 588 -5
copy_from_user 45 40 -5
sys_setsid 128 120 -8
sys_vhangup 32 19 -13
do_exit 1543 1526 -17
bitmap_zero 60 40 -20
arch_local_irq_save 137 117 -20
release_task 674 652 -22
static.spin_unlock_irqrestore 308 260 -48
Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Regression 'tty: fix "IRQ45: nobody cared"'
Regression commit 7b292b4bf9
Function reset_buffer_flags() also invoked during the ioctl(...,TCFLSH,..).
At the time of request we can have full buffers and throttled driver too.
If we don't unthrottle driver, we can get forever throttled driver, because,
after request, we will have empty buffers and throttled driver and
there is no place to unthrottle driver.
It simple reproduce with "pty" pair then one side sleep on tty->write_wait,
and other side do ioctl(...,TCFLSH,..). Then there is no place to do writers wake up.
Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A duplicate definition of the port variable was introduced in the
interrupt handler, which causes the build to break. The fix is to
rename the variable to tport, which is already properly used in
subsequent code.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert the last memory allocation (vt8500_port) to use devm_kzalloc
and remove the fail path cleanup code from vt8500_serial_probe.
Reorder iomem mapping above clk_enable to simplify fail code. The
clock is only enabled if all other resources are available.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART modules on Wondermedia SoCs are connected via a gated clock
source, rather than directly to the 24Mhz reference clock. While
uboot enables UART0 for debugging, other UART ports are unavailable
until the clock is enabled.
This patch checks that a valid clock is actually passed from devicetree,
enables the clock in probe. This change removes the fallback when a
clock was not specified as it doesn't apply any longer (and would only
work if the UART clock was already enabled).
DTSI files are updated for VT8500, WM8505 and WM8650.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many of the tty functions were converted to use a struct tty_port
instead of a struct tty_struct. Update the Tegra driver accordingly to
avoid build breakage.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The write() function could be used by printk(), which is atomic and
tweaking clock there can cause "BUG: sleeping function called from
invalid context".
Signed-off-by: Bao Haojun <hjbao@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fix possible kernel crash if no platform data supplied.
We should not use platform data in this case, instead we will use
default values from private driver structure.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver supports the RocketPort EXPRESS and RocketPort INFINITY
families of PCI/PCIe multiport serial adapters. These adapters use a
"RocketPort 2" ASIC that is not compatible with the original RocketPort
driver (CONFIG_ROCKETPORT).
Tested with the RocketPort EXPRESS Octa DB9 and Quad DB9. Also added an
old RocketPort 8J PCI card to the same system to verify that rocket.c and
rp2.c coexist peacefully.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Matching PCI_ANY_ID causes conflicts with RocketPort 2 adapters, which
are supported by a different driver.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Memory mapped via ioremap call is never released. Rather than add an
iounmap call, change allocation function to devm_request_and_ioremap.
Also, change the error on failure for this call to -EADDRNOTAVAIL rather than
-ENOMEM.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix two instances where the index to vt8500_uart_ports is tested
against > VT8500_MAX_PORTS. Correct usage should be >= VT8500_MAX_PORTS.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pointer tty is dereferened in line 3135, so it is not necessary to check
null again in line 3140.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pointer info is dereferened in line 1009, so it is not necessary to check
null again in line 1012.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Original table in OMAP TRM named "UART Mode Baud Rates, Divisor
Values, and Error Rates" determines modes not for all common baud
rates. E.g. for 1000000 baud rate mode should be 16x, but according to
that table it's determined as 13x. According to current implementation
of mode divisor selection, after requesting 1000000 baudrate from
driver, later one will configure chip to use MODE13 divisor. Assuming
48Mhz as common UART clock speed, MODE13 divisor will effectively give
1230769 baudrate, what is quite far from desired 1000000 baudrate.
While with MODE16 divisor, chip will produce exact 1000000 baudrate.
In old driver that served UART devices (8250.c and serial_core.c) this
divisor could have been configured by user-space program, but in
omap_serial.c driver implementation this ability was not implemented
(afaik, by design) thus disallowing proper usage of MODE16-compatible
baudrates.
Signed-off-by: Alexey Pelykh <alexey.pelykh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit "serial/arc-uart: split probe from probe_earlyprintk" introduced
a build time warning:
"WARNING: vmlinux.o(.data+0x5baa0): Section mismatch in reference from
the variable early_arc_platform_driver to the function
.init.text:arc_serial_probe_earlyprintk()"
While at it - fixed another incorrectly placed initdata annotation.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: fengguang.wu@intel.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fast lookup table to set baudrate is only right when ioclk
is 150MHz. for most platforms, ioclk is 150MHz, but some boards
might set ioclk to other frequency.
so re-calc the clk_div_reg when ioclk is not 150MHz. this patch
also gets clk in probe and puts it in remove.
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for the UART device present in Broadcom TruManage capable
NetXtreme chips (ie: 5761m 5762, and 5725).
This implementation has a hidden transmit FIFO, so running in single-byte
interrupt mode results in too many interrupts. The UART_CAP_HFIFO
capability was added to track this. It continues to reload the THR as long
as the THRE and TSRE bits are set in the LSR up to a specified limit (1024
is used here).
Signed-off-by: Stephen Hurd <shurd@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit bbb63c514a (drivers:tty:fix up
ENOIOCTLCMD error handling) changed the default return value from tty
ioctl to be ENOTTY and not EINVAL. This is appropriate.
But in case of TIOCGPTN for the old BSD ptys glibc started failing
because it expects EINVAL to be returned. Only then it continues to
obtain the pts name the other way around.
So fix this case by explicit return of EINVAL in this case.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Florian Westphal <fw@strlen.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org> # 3.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds keyreset functionality to the sysrq driver. It allows
certain button/key combinations to be used in order to trigger emergency
reboots.
Redefining the '__weak platform_sysrq_reset_seq' variable is required
to trigger the feature. Alternatively keys can be passed to the driver
via a module parameter.
This functionality comes from the keyreset driver submitted by
Arve Hjønnevåg in the Android kernel.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This one was omitted by the "TTY: switch tty_flip_buffer_push" patch
because I did not compile-test mips driver. Now I do.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The default burst is often 1 byte which is not very optimal.
The ideal burst size when using 16550A type port would be
1/2 of fifosize, but this does not work with all Designware
implementations. Setting it to 1/4 fifosize.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are no stubs for ACPI functions so the driver needs to
have this ifdef or it will not compile without ACPI.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove one useless wakeup, and do not use DMA with zero byte
transfers.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty buffer functions are converted to using tty_port
structure instead of struct tty, so we must do the same.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 89c8d91e31 ("tty: localise the lock") I see a dead lock
in one of my dummy_hcd + g_nokia test cases. The first run was usually
okay, the second often resulted in a splat by lockdep and the third was
usually a dead lock.
Lockdep complained about tty->hangup_work and tty->legacy_mutex taken
both ways:
| ======================================================
| [ INFO: possible circular locking dependency detected ]
| 3.7.0-rc6+ #204 Not tainted
| -------------------------------------------------------
| kworker/2:1/35 is trying to acquire lock:
| (&tty->legacy_mutex){+.+.+.}, at: [<c14051e6>] tty_lock_nested+0x36/0x80
|
| but task is already holding lock:
| ((&tty->hangup_work)){+.+...}, at: [<c104f6e4>] process_one_work+0x124/0x5e0
|
| which lock already depends on the new lock.
|
| the existing dependency chain (in reverse order) is:
|
| -> #2 ((&tty->hangup_work)){+.+...}:
| [<c107fe74>] lock_acquire+0x84/0x190
| [<c104d82d>] flush_work+0x3d/0x240
| [<c12e6986>] tty_ldisc_flush_works+0x16/0x30
| [<c12e7861>] tty_ldisc_release+0x21/0x70
| [<c12e0dfc>] tty_release+0x35c/0x470
| [<c1105e28>] __fput+0xd8/0x270
| [<c1105fcd>] ____fput+0xd/0x10
| [<c1051dd9>] task_work_run+0xb9/0xf0
| [<c1002a51>] do_notify_resume+0x51/0x80
| [<c140550a>] work_notifysig+0x35/0x3b
|
| -> #1 (&tty->legacy_mutex/1){+.+...}:
| [<c107fe74>] lock_acquire+0x84/0x190
| [<c140276c>] mutex_lock_nested+0x6c/0x2f0
| [<c14051e6>] tty_lock_nested+0x36/0x80
| [<c1405279>] tty_lock_pair+0x29/0x70
| [<c12e0bb8>] tty_release+0x118/0x470
| [<c1105e28>] __fput+0xd8/0x270
| [<c1105fcd>] ____fput+0xd/0x10
| [<c1051dd9>] task_work_run+0xb9/0xf0
| [<c1002a51>] do_notify_resume+0x51/0x80
| [<c140550a>] work_notifysig+0x35/0x3b
|
| -> #0 (&tty->legacy_mutex){+.+.+.}:
| [<c107f3c9>] __lock_acquire+0x1189/0x16a0
| [<c107fe74>] lock_acquire+0x84/0x190
| [<c140276c>] mutex_lock_nested+0x6c/0x2f0
| [<c14051e6>] tty_lock_nested+0x36/0x80
| [<c140523f>] tty_lock+0xf/0x20
| [<c12df8e4>] __tty_hangup+0x54/0x410
| [<c12dfcb2>] do_tty_hangup+0x12/0x20
| [<c104f763>] process_one_work+0x1a3/0x5e0
| [<c104fec9>] worker_thread+0x119/0x3a0
| [<c1055084>] kthread+0x94/0xa0
| [<c140ca37>] ret_from_kernel_thread+0x1b/0x28
|
|other info that might help us debug this:
|
|Chain exists of:
| &tty->legacy_mutex --> &tty->legacy_mutex/1 --> (&tty->hangup_work)
|
| Possible unsafe locking scenario:
|
| CPU0 CPU1
| ---- ----
| lock((&tty->hangup_work));
| lock(&tty->legacy_mutex/1);
| lock((&tty->hangup_work));
| lock(&tty->legacy_mutex);
|
| *** DEADLOCK ***
Before the path mentioned tty_ldisc_release() look like this:
| tty_ldisc_halt(tty);
| tty_ldisc_flush_works(tty);
| tty_lock();
As it can be seen, it first flushes the workqueue and then grabs the
tty_lock. Now we grab the lock first:
| tty_lock_pair(tty, o_tty);
| tty_ldisc_halt(tty);
| tty_ldisc_flush_works(tty);
so lockdep's complaint seems valid.
The earlier version of this patch took the ldisc_mutex since the other
user of tty_ldisc_flush_works() (tty_set_ldisc()) did this.
Peter Hurley then said that it is should not be requried. Since it
wasn't done earlier, I dropped this part.
The code under tty_ldisc_kill() was executed earlier with the tty lock
taken so it is taken again.
I was able to reproduce the deadlock on v3.8-rc1, this patch fixes the
problem in my testcase. I didn't notice any problems so far.
Cc: Alan Cox <alan@linux.intel.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With ACPI 5.0 we can use the FixedDMA Resource Descriptor to
extract the needed information for DMA support.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for dmaengine API. The drivers can implement the
struct uart_8250_dma member in struct uart_8250_port and
8250.c can take care of the rest.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds support for ACPI 5.0 enumerated Designware UARTs.
ACPI does not deliver information about uart clk, so
delivering it with the driver_data.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Designware UART provides optional Component Parameter
Register that lists most of the capabilities of the UART,
including FIFO size. This uses that register to set FIFO
size for the port before registering it.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trivial cleanup. This makes it easier to add different
methods to enumerate the device, for example ACPI 5.0
enumeration.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This needs to be done in order to later access the
Designware specific registers.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow 8250.c to determine the port type for us. This allows
the driver take advantage of FIFO on Designware UARTs that
have it.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modern UARTs are able to provide information about their
capabilities such as FIFO size. This allows the drivers to
deliver this information to 8250.c when they are registering
ports.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before waking up the tty line discipline idle queue first check if the queue is
active (non empty). This prevents unnecessary entering the critical section in
the wake_up() function and therefore avoid needless scheduling overhead on a
PREEMPT_RT system caused by two processes being in the same critical section.
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
for extern function uart_remove_one_port:
need check pointer whether be NULL, before the main work.
just like what the other extern function uart_add_one_port has done.
uart_add_one_port and uart_remove_one_port are pair
information:
for the callers (such as drivers/tty/serial/jsm: jsm_tty.c, jsm_driver.c)
they realy assume that:
they still can call uart_remove_one_port, after uart_add_one_port failed
we (as an extern function), have to understand it (just like kfree).
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use for_each_compatible_node() macro instead of open coding it.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support for polling work mode, i.e. system is perform
periodical check chip status when IRQ-line is not connected to CPU.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that login from util-linux is forced to drop all references to a
TTY which it wants to hangup (to reach reference count 1) we are
seeing issues with telnet. When login closes its last reference to the
slave PTY, it also resets packet mode on the *master* side. And we
have a race here.
What telnet does is fork+exec of `login'. Then there are two
scenarios:
* `login' closes the slave TTY and resets thus master's packet mode,
but even now telnet properly sets the mode, or
* `telnetd' sets packet mode on the master, `login' closes the slave
TTY and resets master's packet mode.
The former case is OK. However the latter happens in much more cases,
by the order of magnitude to be precise. So when one tries to login to
such a messed telnet setup, they see the following:
inux login:
ogin incorrect
Note the missing first letters -- telnet thinks it is still in the
packet mode, so when it receives "linux login" from `login', it
considers "l" as the type of the packet and strips it.
SuS does not mention how the implementation should behave. Both BSDs I
checked (Free and Net) do not reset the flag upon the last close.
By this I am resurrecting an old bug, see References. We are hitting
it regularly now, i.e. with updated util-linux, ergo login.
Here, I am changing a behavior introduced back in 2.1 times. It would
better have a long time testing before goes upstream.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Bryan Mason <bmason@redhat.com>
References: https://lkml.org/lkml/2009/11/11/223
References: https://bugzilla.redhat.com/show_bug.cgi?id=504703
References: https://bugzilla.novell.com/show_bug.cgi?id=797042
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
spaces are used for indent in 3 places of tty/pty.c, we change it to tab.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
the "\n" in panic message is excess, so we remove it in tty/pty.c as what it
is used in other places.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit f96f7f7f39, at the
request of Jin.
Cc: xiaojin <jin.xiao@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some __devexit markings came in from an older patch, this removes them.
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We test for !dc twice, remove the second test. Coverity found this.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
info in synclink bottom-halves cannot be NULL because it is taken from
work_struct using container_of. Remove the tests.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, the tty is not needed at all places in the ISR. So we can just
request in on demand when really needed.
This cleans TX and RX paths a bit as the indentation level can be
dropped by two now when we also invert the char_count if condition.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
This is the last one: tty_schedule_flip
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
One point is to have less places where we actually need tty pointer.
The other is that low_latency is bound to buffer processing and
buffers are now in tty_port. So it makes sense to move low_latency to
tty_port too.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
tty_insert_flip_string this time.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
tty_insert_flip_char is the next one to proceed. This one is used all
over the code, so the patch is huge.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty pointer in
many call sites. Only tty_port will be needed and hence no more
tty_port_tty_get calls in those paths.
Now 4 string flipping ones are on turn:
* tty_insert_flip_string_flags
* tty_insert_flip_string_fixed_flag
* tty_prepare_flip_string
* tty_prepare_flip_string_flags
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty pointer in
many call sites. Only tty_port will be needed and hence no more
tty_port_tty_get calls in those paths.
Here we start with tty_buffer_request_room.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* DT binding for arc-uart
* With alll the bits in place we can now use DT probing.
Note that there's a bit of kludge right now because earlyprintk portion
of driver can't use the DT infrastrcuture to get resoures/plat_data.
This requires some infrastructre changes to of_flat_ framework
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* is_emulated is now 1st element, rather than last
* also tucked all platform data refs together
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is in preparation for devicetree based probing, where earlyprintk
won't have access to DT serial aliases which the normal probe would
absolutely rely on.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
probe routine could index into port[] with -ve index. The check in
arc_uart_init_one() was too late.
This came to light when trying to port driver to CONFIG_OF, where
bydefault of-core code sets -ve platform dev id and in absence of
DT serial aliases, driver would use the -ve index.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NVIDIA's Tegra has multiple UART controller which supports:
- APB DMA based controller fifo read/write.
- End Of Data interrupt in incoming data to know whether end
of frame achieve or not.
- HW controlled RTS and CTS flow control to reduce SW overhead.
Add serial driver to use all above feature.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Silences the following checkpatch error:
ERROR: that open brace { should be on the previous line
Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This eliminates having an #ifdef returning NULL for the case
when OF is disabled.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The address S3C_VA_UART is a statically ioremapped address. The driver
should not be using this. Instead, the driver should setup a mapping
during probe.
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Detected by cppcheck:
[others/linux/drivers/tty/serial/mxs-auart.c:553]: (style) Same expression on both sides of '||'.
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that support for RM9000 and platforms based on it has been removed,
remove the serial driver for it as well. It's really only been a quirk
for an almost 8250 compatible UART anyway.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
drivers/tty/serial/8250/8250.c | 70 +----------------------------------------
drivers/tty/serial/8250/Kconfig | 9 ------
include/linux/serial_core.h | 1 -
3 files changed, 1 insertion(+), 79 deletions(-)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
before goto out5, soft, control, serial are all assigned to idd
after finish call ioc4_serial_remove_one, all resources are released
we need return instead of go on, or double free
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All the call to gsm->output should be in the tx_lock,
that could avoid potential race from MUX level. But
we have no tx_lock in gsm_send.
This patch is to add tx_lock in gsm_send.
Signed-off-by: xiaojin <jin.xiao@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ralf Baechle