uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically
happen during device probe call.
In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with overlapping major/minor numbers are
included.
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically
happen during device probe call.
In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with overlapping major/minor numbers are
included.
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If DMA is enabled and used, a burst of old data may be seen on the
serial console during "poweroff" or "reboot". uart_flush_buffer()
clears the circular buffer, but sci_port.tx_dma_len is not reset.
This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE -
sci_port.tx_dma_len) bytes.
To fix this, add a .flush_buffer() callback that resets
sci_port.tx_dma_len.
Inspired by commit 31ca2c63fd ("tty/serial: atmel: fix race
condition (TX+DMA)").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This change adds a driver for the 16550-based Aspeed virtual UART
device. We use a similar process to the of_serial driver for device
probe, but expose some VUART-specific functions through sysfs too.
The VUART is two UART 'front ends' connected by their FIFO (no actual
serial line in between). One is on the BMC side (management controller)
and one is on the host CPU side.
This driver is for the BMC side. The sysfs files allow the BMC
userspace, which owns the system configuration policy, to specify at
what IO port and interrupt number the host side will appear to the host
on the Host <-> BMC LPC bus. It could be different on a different system
(though most of them use 3f8/4).
OpenPOWER host firmware doesn't like it when the host-side of the
VUART's FIFO is not drained. This driver only disables host TX discard
mode when the port is in use. We set the VUART enabled bit when we bind
to the device, and clear it on unbind.
We don't want to do this on open/release, as the host may be using this
bit to configure serial output modes, which is independent of whether
the devices has been opened by BMC userspace.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The probing of THRE irq behaviour assumes the other end will be reading
bytes out of the buffer in order to probe the port at driver init. In
some cases the other end cannot be relied upon to read these bytes, so
provide a flag for them to skip this step.
Bit 19 was chosen as the flags are a int and the top bits are taken.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UPF_EXAR_EFR is set globally for each port enumerated by the driver.
Thus, no need to repeat this in individual ->setup() hook.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kernel always writes log messages to console via
serial8250_console_write()->serial8250_console_putchar() which directly
accesses UART_TX register _without_ using DMA.
But, if other processes like systemd using same UART port, then these
writes are handled by a different code flow using 8250_omap driver where
there is provision to use DMA.
It seems that it is possible that both DMA and CPU might simultaneously
put data to UART FIFO and lead to potential loss of data due to FIFO
overflow and weird data corruption. This happens when both kernel
console and userspace tries to write simultaneously to the same UART
port. Therefore, disable DMA on kernel console port to avoid potential
race between CPU and DMA.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds spk_ttyio.c file. It contains a set of functions which implement
those methods in spk_synth struct which relate to sending bytes out using
serial comms. Implementations in this file perform the same function but
using TTY subsystem instead. Currently synths access serial ports, directly
poking standard ISA ports by trying to steal them from serial driver. Some ISA
cards actually need this way of doing it, but most other synthesizers don't,
and can actually work by using the proper TTY subsystem through a new N_SPEAKUP
line discipline. So this adds the methods for drivers to switch to accessing
serial ports through the TTY subsystem, whenever appropriate.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This exports tty_open_by_driver so that it can be called from other
places inside the kernel. The checks for null file pointer are based on
Alan Cox's patch here:
http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1215095.html.
Description below is quoted from it:
"[RFC] tty_port: allow a port to be opened with a tty that has no file handle
Let us create tty objects entirely in kernel space. Untested proposal to
show why all the ideas around rewriting half the uart stack are not needed.
With this a kernel created non file backed tty object could be used to handle
data, and set terminal modes. Not all ldiscs can cope with this as N_TTY in
particular has to work back to the fs/tty layer.
The tty_port code is however otherwise clean of file handles as far as I can
tell as is the low level tty port write path used by the ldisc, the
configuration low level interfaces and most of the ldiscs.
Currently you don't have any exposure to see tty hangups because those are
built around the file layer. However a) it's a fixed port so you probably
don't care about that b) if you do we can add a callback and c) you almost
certainly don't want the userspace tear down/rebuild behaviour anyway.
This should however be sufficient if we wanted for example to enumerate all
the bluetooth bound fixed ports via ACPI and make them directly available.
It doesn't deal with the case of a user opening a port that's also kernel
opened and that would need some locking out (so it returned EBUSY if bound
to a kernel device of some kind). That needs resolving along with how you
"up" or "down" your new bluetooth device, or enumerate it while providing
the existing tty API to avoid regressions (and to debug)."
The exported funtion is used later in this patch set to gain access to tty_struct.
[changed export symbol level - gkh]
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull hw lockdown support from David Howells:
"Annotation of module parameters that configure hardware resources
including ioports, iomem addresses, irq lines and dma channels.
This allows a future patch to prohibit the use of such module
parameters to prevent that hardware from being abused to gain access
to the running kernel image as part of locking the kernel down under
UEFI secure boot conditions.
Annotations are made by changing:
module_param(n, t, p)
module_param_named(n, v, t, p)
module_param_array(n, t, m, p)
to:
module_param_hw(n, t, hwtype, p)
module_param_hw_named(n, v, t, hwtype, p)
module_param_hw_array(n, t, hwtype, m, p)
where the module parameter refers to a hardware setting
hwtype specifies the type of the resource being configured. This can
be one of:
ioport Module parameter configures an I/O port
iomem Module parameter configures an I/O mem address
ioport_or_iomem Module parameter could be either (runtime set)
irq Module parameter configures an I/O port
dma Module parameter configures a DMA channel
dma_addr Module parameter configures a DMA buffer address
other Module parameter configures some other value
Note that the hwtype is compile checked, but not currently stored (the
lockdown code probably won't require it). It is, however, there for
future use.
A bonus is that the hwtype can also be used for grepping.
The intention is for the kernel to ignore or reject attempts to set
annotated module parameters if lockdown is enabled. This applies to
options passed on the boot command line, passed to insmod/modprobe or
direct twiddling in /sys/module/ parameter files.
The module initialisation then needs to handle the parameter not being
set, by (1) giving an error, (2) probing for a value or (3) using a
reasonable default.
What I can't do is just reject a module out of hand because it may
take a hardware setting in the module parameters. Some important
modules, some ipmi stuff for instance, both probe for hardware and
allow hardware to be manually specified; if the driver is aborts with
any error, you don't get any ipmi hardware.
Further, trying to do this entirely in the module initialisation code
doesn't protect against sysfs twiddling.
[!] Note that in and of itself, this series of patches should have no
effect on the the size of the kernel or code execution - that is
left to a patch in the next series to effect. It does mark
annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in
an already existing field"
* tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits)
Annotate hardware config module parameters in sound/pci/
Annotate hardware config module parameters in sound/oss/
Annotate hardware config module parameters in sound/isa/
Annotate hardware config module parameters in sound/drivers/
Annotate hardware config module parameters in fs/pstore/
Annotate hardware config module parameters in drivers/watchdog/
Annotate hardware config module parameters in drivers/video/
Annotate hardware config module parameters in drivers/tty/
Annotate hardware config module parameters in drivers/staging/vme/
Annotate hardware config module parameters in drivers/staging/speakup/
Annotate hardware config module parameters in drivers/staging/media/
Annotate hardware config module parameters in drivers/scsi/
Annotate hardware config module parameters in drivers/pcmcia/
Annotate hardware config module parameters in drivers/pci/hotplug/
Annotate hardware config module parameters in drivers/parport/
Annotate hardware config module parameters in drivers/net/wireless/
Annotate hardware config module parameters in drivers/net/wan/
Annotate hardware config module parameters in drivers/net/irda/
Annotate hardware config module parameters in drivers/net/hamradio/
Annotate hardware config module parameters in drivers/net/ethernet/
...
Here is the "big" TTY/Serial patch updates for 4.12-rc1
Not a lot of new things here, the normal number of serial driver updates
and additions, tiny bugs fixed, and some core files split up to make
future changes a bit easier for Nicolas's "tiny-tty" work.
All of these have been in linux-next for a while. There will be a merge
conflict with include/linux/serdev.h coming from the bluetooth tree
merge, which we knew about, as we wanted some of the serdev changes to
go in through that tree. I'll send the expected merge result as a
follow-on message.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here is the "big" TTY/Serial patch updates for 4.12-rc1
Not a lot of new things here, the normal number of serial driver
updates and additions, tiny bugs fixed, and some core files split up
to make future changes a bit easier for Nicolas's "tiny-tty" work.
All of these have been in linux-next for a while"
* tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (62 commits)
serial: small Makefile reordering
tty: split job control support into a file of its own
tty: move baudrate handling code to a file of its own
console: move console_init() out of tty_io.c
serial: 8250_early: Add earlycon support for Palmchip UART
tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
vt: make mouse selection of non-ASCII consistent
vt: set mouse selection word-chars to gpm's default
imx-serial: Reduce RX DMA startup latency when opening for reading
serial: omap: suspend device on probe errors
serial: omap: fix runtime-pm handling on unbind
tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
serial: samsung: Remove useless spinlock
serial: samsung: Add missing checks for dma_map_single failure
serial: samsung: Use right device for DMA-mapping calls
serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
tty: fix comment typo s/repsonsible/responsible/
tty: amba-pl011: Fix spurious TX interrupts
serial: xuartps: Enable clocks in the pm disable case also
serial: core: Re-use struct uart_port {name} field
...
While examining output from trial builds with -Wformat-security enabled,
many strings were found that should be defined as "const", or as a char
array instead of char pointer. This makes some static analysis easier,
by producing fewer false positives.
As these are all trivial changes, it seemed best to put them all in a
single patch rather than chopping them up per maintainer.
Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Jes Sorensen <jes@trained-monkey.org> [runner.c]
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Salil Mehta <salil.mehta@huawei.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kejian Yan <yankejian@huawei.com>
Cc: Daode Huang <huangdaode@hisilicon.com>
Cc: Qianqian Xie <xieqianqian@huawei.com>
Cc: Philippe Reynes <tremyfr@gmail.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Christian Gromm <christian.gromm@microchip.com>
Cc: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Cc: Jason Litzinger <jlitzingerdev@gmail.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Fix sparse warnings in drivers/of/.
- Add more overlay unittests.
- Update dtc to v1.4.4-8-g756ffc4f52f6. This adds more checks on dts
files such as unit-address formatting and stricter character sets for
node and property names.
- Add a common DT modalias function.
- Move trivial-devices.txt up and out of i2c dir.
- ARM NVIC interrupt controller binding.
- Vendor prefixes for Sensirion, Dioo, Nordic, ROHM.
- Correct some binding file locations.
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Merge tag 'devicetree-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull DeviceTree updates from Rob Herring:
- fix sparse warnings in drivers/of/
- add more overlay unittests
- update dtc to v1.4.4-8-g756ffc4f52f6. This adds more checks on dts
files such as unit-address formatting and stricter character sets for
node and property names
- add a common DT modalias function
- move trivial-devices.txt up and out of i2c dir
- ARM NVIC interrupt controller binding
- vendor prefixes for Sensirion, Dioo, Nordic, ROHM
- correct some binding file locations
* tag 'devicetree-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (24 commits)
of: fix sparse warnings in fdt, irq, reserved mem, and resolver code
of: fix sparse warning in of_pci_range_parser_one
of: fix sparse warnings in of_find_next_cache_node
of/unittest: Missing unlocks on error
of: fix uninitialized variable warning for overlay test
of: fix unittest build without CONFIG_OF_OVERLAY
of: Add unit tests for applying overlays
of: per-file dtc compiler flags
fpga: region: add missing DT documentation for config complete timeout
of: Add vendor prefix for ROHM Semiconductor
of: fix "/cpus" reference leak in of_numa_parse_cpu_nodes()
of: Add vendor prefix for Nordic Semiconductor
dt-bindings: arm,nvic: Binding for ARM NVIC interrupt controller on Cortex-M
dtc: update warning settings for new bus and node/property name checks
scripts/dtc: Update to upstream version v1.4.4-8-g756ffc4f52f6
scripts/dtc: automate getting dtc version and log in update script
of: Add function for generating a DT modalias with a newline
of: fix of_device_get_modalias returned length when truncating buffers
Documentation: devicetree: move trivial-devices out of I2C realm
dt-bindings: add vendor prefix for Dioo
..
Tetsuo has reported that sysrq triggered OOM killer will print a
misleading information when no tasks are selected:
sysrq: SysRq : Manual OOM execution
Out of memory: Kill process 4468 ((agetty)) score 0 or sacrifice child
Killed process 4468 ((agetty)) total-vm:43704kB, anon-rss:1760kB, file-rss:0kB, shmem-rss:0kB
sysrq: SysRq : Manual OOM execution
Out of memory: Kill process 4469 (systemd-cgroups) score 0 or sacrifice child
Killed process 4469 (systemd-cgroups) total-vm:10704kB, anon-rss:120kB, file-rss:0kB, shmem-rss:0kB
sysrq: SysRq : Manual OOM execution
sysrq: OOM request ignored because killer is disabled
sysrq: SysRq : Manual OOM execution
sysrq: OOM request ignored because killer is disabled
sysrq: SysRq : Manual OOM execution
sysrq: OOM request ignored because killer is disabled
The real reason is that there are no eligible tasks for the OOM killer
to select but since commit 7c5f64f844 ("mm: oom: deduplicate victim
selection code for memcg and global oom") the semantic of out_of_memory
has changed without updating moom_callback.
This patch updates moom_callback to tell that no task was eligible which
is the case for both oom killer disabled and no eligible tasks. In
order to help distinguish first case from the second add printk to both
oom_killer_{enable,disable}. This information is useful on its own
because it might help debugging potential memory allocation failures.
Fixes: 7c5f64f844 ("mm: oom: deduplicate victim selection code for memcg and global oom")
Link: http://lkml.kernel.org/r/20170404134705.6361-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A function in kernel/bpf/syscall.c which got a bug fix in 'net'
was moved to kernel/bpf/verifier.c in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image. Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.
To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify. The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.
Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.
This patch annotates drivers in drivers/tty/.
Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jiri Slaby <jslaby@suse.com>
cc: linux-serial@vger.kernel.org
Move 21285 entry down alongside other UART drivers to be more consistent
with the rest of the file. It is kept before 8250 though, to preserve the
existing link ordering between those two.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This makes it easier for job control to become optional and/or usable
independently from tty_io.c, as well as providing a nice purpose
separation. No logical changes from this patch.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To allow reuse without the rest of the tty_ioctl code.
No logical changes from this patch.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All the console driver handling code lives in printk.c.
Move console_init() there as well so console support can still be used
when the TTY code is configured out. No logical changes from this patch.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Define an OF early console for Palmchip UART, which can be enabled
by passing "earlycon" on the boot command line.
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Define a new early console name for Qualcomm Datacenter Technologies
QDF2400 SOCs affected by erratum 44, instead of piggy-backing on "pl011".
Previously, to enable traditional (non-SPCR) earlycon, the documentation
said to specify "earlycon=pl011,<address>,qdf2400_e44", but the code was
broken and this didn't actually work.
So instead, the method for specifying the E44 work-around with traditional
earlycon is "earlycon=qdf2400_e44,<address>". Both methods of earlycon
are now enabled with the same function.
Fixes: e53e597fd4 ("tty: pl011: fix earlycon work-around for QDF2400 erratum 44")
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Cc: stable <stable@vger.kernel.org> # 4.11
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add method, which waits until the transmission buffer has been sent.
Note, that the change in ttyport_write_wakeup is related, since
tty_wait_until_sent will hang without that change.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The UPF_BOOT_AUTOCONF flag is needed for proper
flow control support.
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since forever, gpm was this code's only user, and it overrides the table on
start so the default was never seen -- until Bill Allombert's "consolation"
came in. The in-kernel set is "A-Za-z0-9_" which fails to catch typical
file names, etc. Let's change this to gpm's conservative default, ie
"-A-Za-z0-9_./"; most terminals include more, for example xfce4-terminal has
"-A-Za-z0-9,./?%&#:_=+@~".
There's some discussion at https://bugs.debian.org/846587
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reduce RX DMA start latency for the first reception when port is opened
for reading. Instead of waiting for an interrupt signaling data on RX
FIFO or data too old on RX FIFO, start RX DMA immediately when the
serial port is opened for reading.
Before this patch, the average RX DMA latency for the first reception
was 42489 microseconds with a standard deviation of 25721 microseconds
in 36 samples.
After the patch the average RX DMA latency for the first reception, when
the serial port is opened for reading, is 653 microseconds with a
standard deviation of 294 microseconds in 36 samples.
Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to actually suspend the device before returning after a failed
(or deferred) probe.
Note that autosuspend must be disabled before runtime pm is disabled in
order to balance the usage count due to a negative autosuspend delay as
well as to make the final put suspend the device synchronously.
Fixes: 388bc26226 ("omap-serial: Fix the error handling in the omap_serial probe")
Cc: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An unbalanced and misplaced synchronous put was used to suspend the
device on driver unbind, something which with a likewise misplaced
pm_runtime_disable leads to external aborts when an open port is being
removed.
Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010
...
[<c046e760>] (serial_omap_set_mctrl) from [<c046a064>] (uart_update_mctrl+0x50/0x60)
[<c046a064>] (uart_update_mctrl) from [<c046a400>] (uart_shutdown+0xbc/0x138)
[<c046a400>] (uart_shutdown) from [<c046bd2c>] (uart_hangup+0x94/0x190)
[<c046bd2c>] (uart_hangup) from [<c045b760>] (__tty_hangup+0x404/0x41c)
[<c045b760>] (__tty_hangup) from [<c045b794>] (tty_vhangup+0x1c/0x20)
[<c045b794>] (tty_vhangup) from [<c046ccc8>] (uart_remove_one_port+0xec/0x260)
[<c046ccc8>] (uart_remove_one_port) from [<c046ef4c>] (serial_omap_remove+0x40/0x60)
[<c046ef4c>] (serial_omap_remove) from [<c04845e8>] (platform_drv_remove+0x34/0x4c)
Fix this up by resuming the device before deregistering the port and by
suspending and disabling runtime pm only after the port has been
removed.
Also make sure to disable autosuspend before disabling runtime pm so
that the usage count is balanced and device actually suspended before
returning.
Note that due to a negative autosuspend delay being set in probe, the
unbalanced put would actually suspend the device on first driver unbind,
while rebinding and again unbinding would result in a negative
power.usage_count.
Fixes: 7e9c8e7dbf ("serial: omap: make sure to suspend device before remove")
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UPF_BOOT_AUTOCONF flag is needed for proper
flow control support.
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Spinlock taken only for dma_map_single() for TX buffer is completely
useless and doesn't protect anything, so remove it to simplify the code.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds missing checks for dma_map_single() failure and proper error
reporting. Although this issue was harmless on ARM architecture, it is always
good to use the DMA mapping API in a proper way. This patch fixes the following
DMA API debug warning:
WARNING: CPU: 1 PID: 3785 at lib/dma-debug.c:1171 check_unmap+0x8a0/0xf28
dma-pl330 121a0000.pdma: DMA-API: device driver failed to check map error[device address=0x000000006e0f9000] [size=4096 bytes] [mapped as single]
Modules linked in:
CPU: 1 PID: 3785 Comm: (agetty) Tainted: G W 4.11.0-rc1-00137-g07ca963-dirty #59
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c072a114>] (check_unmap+0x8a0/0xf28)
[<c072a114>] (check_unmap) from [<c072a834>] (debug_dma_unmap_page+0x98/0xc8)
[<c072a834>] (debug_dma_unmap_page) from [<c0803874>] (s3c24xx_serial_shutdown+0x314/0x52c)
[<c0803874>] (s3c24xx_serial_shutdown) from [<c07f5124>] (uart_port_shutdown+0x54/0x88)
[<c07f5124>] (uart_port_shutdown) from [<c07f522c>] (uart_shutdown+0xd4/0x110)
[<c07f522c>] (uart_shutdown) from [<c07f6a8c>] (uart_hangup+0x9c/0x208)
[<c07f6a8c>] (uart_hangup) from [<c07c426c>] (__tty_hangup+0x49c/0x634)
[<c07c426c>] (__tty_hangup) from [<c07c78ac>] (tty_ioctl+0xc88/0x16e4)
[<c07c78ac>] (tty_ioctl) from [<c03b5f2c>] (do_vfs_ioctl+0xc4/0xd10)
[<c03b5f2c>] (do_vfs_ioctl) from [<c03b6bf4>] (SyS_ioctl+0x7c/0x8c)
[<c03b6bf4>] (SyS_ioctl) from [<c010b4a0>] (ret_fast_syscall+0x0/0x3c)
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.10+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Driver should provide its own struct device for all DMA-mapping calls instead
of extracting device pointer from DMA engine channel. Although this is harmless
from the driver operation perspective on ARM architecture, it is always good
to use the DMA mapping API in a proper way. This patch fixes following DMA API
debug warning:
WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4
samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4)
[<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8)
[<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8)
[<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c)
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which
is the reset default) and the opposite side pulls the respective line to
its active level the irq triggers after it is requested in .probe.
These irqs were already disabled in .startup but this might be too late.
Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is
done very late which is critical as it also controls direction of some
pins.
So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken
irqs in DTE mode there before requesting irqs.
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On SMP systems, we see a lot of spurious TX interrupts when a
program generates a steady stream of output to the pl011 UART.
The problem can be easily seen when one CPU generates the output
while another CPU handles the pl011 interrupts, and the rate of
output is low enough not to fill the TX FIFO. The problem seems
to be:
-- CPU a -- -- CPU b --
(take port lock)
pl011_start_tx
pl011_start_tx_pio
enable TXIM in REG_IMSC -> causes uart tx intr (pl011_int)
pl011_tx_chars pl011_int
...tx chars, all done... (wait for port lock)
pl011_stop_tx .
disable TXIM .
(release port lock) -> (take port lock)
check for TXIM, not enabled
(release port lock)
return IRQ_NONE
Enabling the TXIM in pl011_start_tx_pio() causes the interrupt
to be generated and delivered to CPU b, even though pl011_tx_chars()
is able to complete the TX and then disable the tx interrupt.
Fix this by enabling TXIM only after pl011_tx_chars, if it is needed.
pl011_tx_chars will return a boolean indicating whether the TX
interrupts have to be enabled.
Debugged-by: Vijaya Kumar <Vijaya.Kumar@cavium.com>
Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When Power management is disabled then the clocks are not getting
enabled. This patch enables it for the !PM case also.
While at it also pm_runtime_set_active is called before
calling pm_runtime_enable.
Reported-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since we have port name stored in struct uart_port, we better to use
that one instead of open coding.
This will make it one place source for easier maintenance or
modifications.
While here, replace printk(KERN_INFO ) by pr_info(). It seems last printk()
call in serial_core.c.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add serdev_device_write() a blocking call allowing to transfer
arbitraty amount of data (potentially exceeding amount that
serdev_device_write_buf can process in a single call)
To support that, also add serdev_device_write_wakeup().
Drivers wanting to use full extent of serdev_device_write
functionality are expected to provide serdev_device_write_wakeup() as
a sole handler of .write_wakeup event or call it as a part of driver's
custom .write_wakeup code.
Because serdev_device_write() subroutine is a superset of
serdev_device_write_buf() the patch re-impelements latter is terms of
the former. For drivers wanting to just use serdev_device_write_buf()
.write_wakeup handler is optional.
Cc: cphealy@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SPRD_TIMEOUT was 256, which is too small to wait until the status
switched to workable in a while loop, so that the earlycon could
not work correctly.
Signed-off-by: Wei Qiao <wei.qiao@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mostly simple cases of overlapping changes (adding code nearby,
a function whose name changes, for example).
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit d6580a9f15 ("kexec: sysrq: simplify sysrq-c handler"),
the sysrq handler for the 'c' key has been sysrq_crash_op. Debugging
code in the ibm_emac driver also tries to register a handler for the 'c'
key, but this has no effect because register_sysrq_key() doesn't replace
existing handlers. Since evidently no one has cared enough to fix this
in the last 8 years, and it's very rare for drivers to register sysrq
handlers (for good reason), just remove the dead code.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull scheduler fixes from Thomas Gleixner:
"This update provides:
- make the scheduler clock switch to unstable mode smooth so the
timestamps stay at microseconds granularity instead of switching to
tick granularity.
- unbreak perf test tsc by taking the new offset into account which
was added in order to proveide better sched clock continuity
- switching sched clock to unstable mode runs all clock related
computations which affect the sched clock output itself from a work
queue. In case of preemption sched clock uses half updated data and
provides wrong timestamps. Keep the math in the protected context
and delegate only the static key switch to workqueue context.
- remove a duplicate header include"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/headers: Remove duplicate #include <linux/sched/debug.h> line
sched/clock: Fix broken stable to unstable transfer
sched/clock, x86/perf: Fix "perf test tsc"
sched/clock: Fix clear_sched_clock_stable() preempt wobbly
The work-around for the Qualcomm Datacenter Technologies QDF2400
erratum 44 sets the "qdf2400_e44_present" global variable if the
work-around is needed. However, this check does not happen until after
earlycon is initialized, which means the work-around is not
used, and the console hangs as soon as it displays one character.
Fixes: d8a4995bce ("tty: pl011: Work around QDF2400 E44 stuck BUSY bit")
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit d0aeaa83f0 ("serial: exar:
split out the exar code from 8250_pci") the exar driver got its own
Kconfig. However the text for the new option was never changed from
the original 8250_PCI text, and hence it appears confusing when you
get asked the same question twice:
8250/16550 PCI device support (SERIAL_8250_PCI) [Y/n/m/?] (NEW)
8250/16550 PCI device support (SERIAL_8250_EXAR) [Y/n/m] (NEW)
Adding to the confusion, is that there is no help text for this new
option to indicate it is specific to a certain family of cards.
Fix both issues at the same time, as well as the space vs. tab issues
introduced in the same commit.
Fixes: d0aeaa83f0 ("serial: exar: split out the exar code from 8250_pci")
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A side effect of 89d8232411 ("tty/serial: atmel_serial: BUG: stop DMA
from transmitting in stop_tx") is that the console can be called with
TX path disabled. Then the system would hang trying to push charecters
out in atmel_console_putchar().
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Fixes: 89d8232411 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting
in stop_tx")
Cc: stable <stable@vger.kernel.org> #4.4+
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If uart_flush_buffer() is called between atmel_tx_dma() and
atmel_complete_tx_dma(), the circular buffer has been cleared, but not
atmel_port->tx_len.
That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE -
atmel_port->tx_len) bytes).
Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The reference manual for the i.MX28 recommends to calculate the divisor
as
divisor = (UARTCLK * 32) / baud rate, rounded to the nearest integer
, so let's do this. For a typical setup of UARTCLK = 24 MHz and baud
rate = 115200 this changes the divisor from 6666 to 6667 and so the
actual baud rate improves from 115211.521 Bd (error ≅ 0.01 %) to
115194.240 Bd (error ≅ 0.005 %).
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The console write code is not entirely race free (e.g. the operations
to disabling the UART interrupts are not atomic) hence locking is
required. This has been become apparent with the PREEMPT RT patchset
applied: With the fully preemptible kernel configuration the system
often ended up in a freeze already at startup.
Disable interrupts and lock using read_lock_irqsave. Try to lock in
the sysrq/oops case, but don't bother if locking fails.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_uart.
Add earlycon support to altera_uart so that other archs may use it.
Also, this (together with the corresponding patch for altera_jtaguart)
will allow the early printk implementation in arch/nios2 to be removed
in a future patch.
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
BugLink: http://bugs.launchpad.net/bugs/869017
Console blanking is not enabling DPMS power saving (thereby negating any
power-saving benefit), and is simply turning the screen content blank. This
means that any crash output is invisible which is unhelpful on a server
(virtual or otherwise).
Furthermore, CRT burn in concerns should no longer govern the default case.
Affected users could always set consoleblank on the kernel command line.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Using dev_name() as IRQ name during request_irq() might be misleading in
case of serial over PCI. Therefore identify serial port IRQ using
uart_port's name field. This will help mapping IRQs to appropriate
ttySN(where N is the serial port index) instances.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a field to store name of uart_port that can be used to easily
identify UART port instances on a system that has more than one UART
instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N
is number that particular UART instance.
This field will be useful when printing debug info for a particular port
or in register IRQs with unique IRQ name. Port name is populated during
uart_add_one_port().
Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MSI needs it as well.
Should have no practical impact, though, as DMA is always available on
the Quark. But given the few users of pci_alloc_irq_vectors so far, this
incorrect pattern may spread otherwise.
Fixes: 3f3a46951e ("serial: 8250_lpss: set PCI master only for private DMA")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a UART has dedicated RTS/CTS pins, and hardware control flow is
disabled (or AUTORTS is not yet effective), changing any serial port
configuration deasserts RTS, as .set_termios() calls sci_init_pins().
To fix this, consider the current (AUTO)RTS state when (re)initializing
the pins. Note that for SCIFA/SCIFB, AUTORTS needs explicit
configuration of the RTS# pin function, while (H)SCIF handles this
automatically.
Fixes: d2b9775d79 ("serial: sh-sci: Correct pin initialization on (H)SCIF")
Fixes: e9d7a45a03 ("serial: sh-sci: Add pin initialization for SCIFA/SCIFB")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised. However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.
To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).
Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc25 ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the .set_termios() callback resets the UART, it first waits (busy
loops) until all characters in the transmit FIFO have been transmitted,
to prevent a port configuration change from impacting these characters.
However, if the UART has dedicated RTS/CTS hardware flow control
enabled, these characters may have been stuck in the FIFO due to CTS not
being asserted by the remote side.
- When a new user opens the port, .set_termios() is called while
transmission is still disabled, leading to an infinite loop:
NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!
- When an active user changes port configuration without waiting for
the draining of the transmit FIFO, this may also block indefinitely,
until CTS is asserted by the remote side.
This has been observed with SCIFA (on r8a7740/armadillo), and SCIFB and
HSCIF (on r8a7791/koelsch).
To fix this, remove the code that waits for the draining of the transmit
FIFO.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9600 is old school.
Most applications use 115200 as the default baud these days.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock is a sleeping lock and local_irq_save() is not the
standard implementation now. Working for both -RT and non
RT.
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hvc_remove() takes a spin lock first then acquires the console
semaphore. This situation can easily lead to a deadlock scenario
where we call scheduler with spin lock held.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Free any saved termios data when registering a tty device so that the
termios state is reset when reusing a minor number.
This is useful for hot-pluggable buses such as USB where it does not
make much sense to reuse saved termios data from an unrelated device
when a new device is later plugged in.
This specifically avoids a situation where the new device does not have
the carrier-detect signal wired, but the saved termios state has CLOCAL
cleared, effectively preventing the port from being opened in blocking
mode as noted by Jan Kundrát <jan.kundrat@cesnet.cz>.
Note that clearing the saved data at deregistration would not work as
the device could still be open.
Also note that the termios data is not reset for drivers with
TTY_DRIVER_DYNAMIC_ALLOC set (e.g. legacy pty) as their character device
is registered at driver registration and could theoretically already
have been opened (and pty termios state is never saved anyway).
Reported-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop comments about tty-driver termios_locked structures, which have
been outdated since commit fe6e29fdb1 ("tty: simplify ktermios
allocation").
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty class device is currently not registered until after the
character device has been registered thereby leaving a small window
were a racing open could end up with a NULL tty->dev pointer due to the
class-device lookup failing in alloc_tty_struct.
Close this race by registering the class device before the character
device while making sure to defer the user-space uevent notification
until after the character device has been registered.
Note that some tty drivers expect a valid tty->dev and would misbehave
or crash otherwise. Some line disciplines also currently dereference the
class device unconditionally despite the fact that not every tty is
guaranteed to have one (Unix98 pty), but this is being fixed separately.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 71472fa9c5. It caused
merge issues, and Dmitry found some review issues.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are some tty and serial driver fixes for 4.11-rc4. One of these
fix a long-standing issue in the ldisc code that was found by Dmitry
Vyukov with his great fuzzing work. The other fixes resolve other
reported issues, and there is one revert of a patch in 4.11-rc1 that
wasn't correct.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH:
"Here are some tty and serial driver fixes for 4.11-rc4.
One of these fix a long-standing issue in the ldisc code that was
found by Dmitry Vyukov with his great fuzzing work. The other fixes
resolve other reported issues, and there is one revert of a patch in
4.11-rc1 that wasn't correct.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: fix data race in tty_ldisc_ref_wait()
tty: don't panic on OOM in tty_set_ldisc()
Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
tty: acpi/spcr: QDF2400 E44 checks for wrong OEM revision
serial: 8250_dw: Fix breakage when HAVE_CLK=n
serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
The modalias sysfs attr is lacking a newline for DT aliases on platform
devices. The macio and ibmebus correctly add the newline, but open code it.
Introduce a new function, of_device_modalias(), that fills the buffer with
the modalias including the newline and update users of the old
of_device_get_modalias function.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Set the parent on the Altera A10SR driver, also fix
high level IRQs.
- Fix error path on the mockup driver.
- Compilation noise about unused functions fixed.
- Fix missed interrupts on the MCP23S08 expander, this is also
tagged for stable.
- Retire the interrim helpers devm_get_gpiod_from_child() used
to smoothen merging in the merge window.
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Merge tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO fixes from Linus Walleij:
"Here is the first set of GPIO fixes for 4.11. It was delayed a bit
beacuse I was chicken when linux-next was not rotating last week.
This hits the ST serial driver in drivers/tty/serial and that has an
ACK from Greg, he suggested to keep the old GPIO fwnode API around to
smoothen things in the merge Windod and those have now served their
purpose so we take them out and convert the last driver to the new
API.
Apart from that it's fixes as usual.
Summary:
- set the parent on the Altera A10SR driver, also fix high level
IRQs.
- fix error path on the mockup driver.
- compilation noise about unused functions fixed.
- fix missed interrupts on the MCP23S08 expander, this is also tagged
for stable.
- retire the interrim helpers devm_get_gpiod_from_child() used to
smoothen merging in the merge window"
* tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio:mcp23s08 Fixed missing interrupts
serial: st-asc: Use new GPIOD API to obtain RTS pin
gpio: altera: Use handle_level_irq when configured as a level_high
gpio: xgene: mark PM functions as __maybe_unused
gpio: mockup: return -EFAULT if copy_from_user() fails
gpio: altera-a10sr: Set gpio_chip parent property
As of commit bb475230b8 ("reset: make optional functions really
optional"), the reset framework API calls use NULL pointers to describe
optional, non-present reset controls.
This allows to return errors from devm_reset_control_get_optional and to
call reset_control_(de)assert unconditionally.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coverity complains about uart_state checks in polling functions. And it
is indeed correct. We do something like this:
struct uart_state *state = drv->state + line;
if (!state)
return;
Adding 'line' to drv->state would move the potential NULL pointer to
something near NULL and the check is useless. Even if we checked pure
drv->state, nothing guarantees it is not freed and NULLed after the
check. So if the only user of this interface (kgdboc) needs to assure
something, this is neither the correct thing, nor place to do so.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fintek F81866 supports baud rates higher than 115200 but needs to raise
it's clock speed from 1.84 to 14.76 MHz.
This is eight times faster, so gives 921600 as resulting baud_base.
F81866 clock register 0xf2:
Bit 7-2 reserved
Bit 1-0 00: 1.8432MHz
01: 18.432MHz
10: 24MHz
11: 14.769MHz
Signed-off-by: Lukas Redlinger <rel+kernel@agilox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While using emacs, cat or others' commands in konsole with recent
kernels, I have met many times that CTRL-C freeze konsole. After
konsole freeze I can't type anything, then I have to open a new one,
it is very annoying.
See bug report:
https://bugs.kde.org/show_bug.cgi?id=175283
The platform in that bug report is Solaris, but now the pty in linux
has the same problem or the same behavior as Solaris :)
It has high possibility to trigger the problem follow steps below:
Note: In my test, BigFile is a text file whose size is bigger than 1G
1:open konsole
1:cat BigFile
2:CTRL-C
After some digging, I find out the reason is that commit 1d1d14da12
("pty: Fix buffer flush deadlock") changes the behavior of pty_flush_buffer.
Thread A Thread B
-------- --------
1:n_tty_poll return POLLIN
2:CTRL-C trigger pty_flush_buffer
tty_buffer_flush
n_tty_flush_buffer
3:attempt to check count of chars:
ioctl(fd, TIOCINQ, &available)
available is equal to 0
4:read(fd, buffer, avaiable)
return 0
5:konsole close fd
Yes, I know we could use the same patch included in the BUG report as
a workaround for linux platform too. But I think the data in ldisc is
belong to application of another side, we shouldn't clear it when we
want to flush write buffer of this side in pty_flush_buffer. So I think
it is better to disable ldisc flush in pty_flush_buffer, because its new
hehavior bring no benefit except that it mess up the behavior between
POLLIN, and TIOCINQ or FIONREAD.
Also I find no flush_buffer function in others' tty driver has the
same behavior as current pty_flush_buffer.
Fixes: 1d1d14da12 ("pty: Fix buffer flush deadlock")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The number of uartlites should be set by a kernel parameter instead of
using a #define. This allows the user to set the number of uartlites
using only kconfig and not modifying kernel source.
The uartlite is used by FPGAs that support a basically unlimited number
of uarts so limiting it at 16 dosn't make sense as users might need more
than that.
Signed-off-by: Sam Povilus <kernel.development@povil.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The core handles the clocking now. Remove the clock disable in
suspend. In resume we enable the clocks and disable after register
write.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_jtaguart
(and altera_uart for that matter).
Add earlycon support to altera_jtaguart so that other archs may use it. Also,
this will allow the early printk implementation in arch/nios2 to eventually be
removed in a future patch.
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of using a private copy of struct net_device_stats in struct
gsm_mux_net, use stats from struct net_device. Also remove
the now unnecessary .ndo_get_stats function.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To enable eventual removal of pr_warning
This makes pr_warn use consistent for drivers/tty
Prior to this patch, there were 2 uses of pr_warning and
23 uses of pr_warn in drivers/tty
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_ldisc_ref_wait() checks tty->ldisc under tty->ldisc_sem.
But if ldisc==NULL it releases them sem and reloads
tty->ldisc without holding the sem. This is wrong and
can lead to returning non-NULL ldisc without protection.
Don't reload tty->ldisc second time.
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If tty_ldisc_open() fails in tty_set_ldisc(), it tries to go back
to the old discipline or N_TTY. But that can fail as well, in such
case it panics. This is not a graceful way to handle OOM.
Leave ldisc==NULL if all attempts fail instead.
Also use existing tty_ldisc_reinit() helper function instead of
tty_ldisc_restore(). Also don't WARN/BUG in tty_ldisc_reinit()
if N_TTY fails, which would have the same net effect of bringing
kernel down on OOM. Instead print a single line message about
what has happened.
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The original patch makes the condition always true, so it is wrong.
It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.
s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.
This reverts commit aea9a80ba9.
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The commits mentioned below adapt the GPIO API to allow more information
to be passed directly through devm_get_gpiod_from_child() in the first
instance. This facilitates the removal of subsequent calls, such as
gpiod_direction_output(). This patch firstly moves to utilise the new
API and secondly removes the now superfluous call do set the direction.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Also drop the header file dummies that only this driver was using]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Passing "serial" as name during request_irq() results in all serial port
irqs have same name. This does not help much to easily identify which
irq belongs to which serial port instance. Therefore pass dev_name()
during request_irq() so that better identifiable name is listed for
serial ports in cat /proc/interrupts output.
Output of cat /proc/interrupts
Before this patch:
26: 689 0 GICv2 309 Edge serial
After this patch:
26: 696 0 GICv2 309 Edge 2530c00.serial
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atmel_serial.h is only used by atmel_serial.c, so there's no need for
it to lie in include/linux.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
struct cache is only used in suspend/resume. Exclude it when PM is not
selected.
Suggested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The samx7 family uses the same UART/USART IP as the at91/sama5 families but
has 8 of those.
Suggested-by: Szemző András <sza@esh.hu>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes an issue that kernel panic happens when DMA is enabled
and we press enter key while the kernel booting on the serial console.
* An interrupt may occur after sci_request_irq().
* DMA transfer area is initialized by setup_timer() in sci_request_dma()
and used in interrupt.
If an interrupt occurred between sci_request_irq() and setup_timer() in
sci_request_dma(), DMA transfer area has not been initialized yet.
So, this patch changes the order of sci_request_irq() and
sci_request_dma().
Fixes: 73a19e4c03 ("serial: sh-sci: Add DMA support.")
Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
[Shimoda changes the commit log]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The original patch makes the condition always true, so it is wrong.
It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.
s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.
This reverts commit aea9a80ba9.
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be
used") recently broke the 8250_dw driver on platforms which don't select
HAVE_CLK, as dw8250_set_termios() gets confused by the behaviour of the
fallback HAVE_CLK=n clock API in linux/clk.h which pretends everything
is fine but returns (valid) NULL clocks and 0 HZ clock rates.
That 0 rate is written into the uartclk resulting in a crash at boot,
e.g. on Cavium Octeon III based UTM-8 we get something like this:
1180000000800.serial: ttyS0 at MMIO 0x1180000000800 (irq = 41, base_baud = 25000000) is a OCTEON
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1 at drivers/tty/serial/serial_core.c:441 uart_get_baud_rate+0xfc/0x1f0
...
Call Trace:
...
[<ffffffff8149c2e4>] uart_get_baud_rate+0xfc/0x1f0
[<ffffffff814a5098>] serial8250_do_set_termios+0xb0/0x440
[<ffffffff8149c710>] uart_set_options+0xe8/0x190
[<ffffffff814a6cdc>] serial8250_console_setup+0x84/0x158
[<ffffffff814a11ec>] univ8250_console_setup+0x54/0x70
[<ffffffff811901a0>] register_console+0x1c8/0x418
[<ffffffff8149f004>] uart_add_one_port+0x434/0x4b0
[<ffffffff814a1af8>] serial8250_register_8250_port+0x2d8/0x440
[<ffffffff814aa620>] dw8250_probe+0x388/0x5e8
...
The clock API is defined such that NULL is a valid clock handle so it
wouldn't be right to check explicitly for NULL. Instead treat a
clk_round_rate() return value of 0 as an error which prevents uartclk
being overwritten.
Fixes: 6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be used")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-serial@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jason Uy <jason.uy@broadcom.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
clk_round_rate returns a signed long and may possibly return errors
in it, for example if there is no possible rate.
Till now dw8250_set_termios ignored any error, the signednes and would
just use the value as input to clk_set_rate. This of course falls apart
if there is an actual error, so check for errors and only try to set
a rate if the value is actually valid.
This turned up on some Rockchip platforms after commit
6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be used")
enabled set_termios callback in all cases, not only ACPI.
Fixes: 6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be used")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If DMA is not available (even when configured in DeviceTree), the driver
will fail the startup procedure thus making serial console not
available.
For example this causes boot failure on QEMU ARMv7 (Exynos4210, SMDKC210):
[ 1.302575] OF: amba_device_add() failed (-19) for /amba/pdma@12680000
...
[ 11.435732] samsung-uart 13800000.serial: DMA request failed
[ 72.963893] samsung-uart 13800000.serial: DMA request failed
[ 73.143361] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000
DMA is not necessary for serial to work, so continue with UART startup
after emitting a warning.
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently N_HDLC line discipline uses a self-made singly linked list for
data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after
an error.
The commit be10eb7589
("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf.
After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put
one data buffer to tx_free_buf_list twice. That causes double free in
n_hdlc_release().
Let's use standard kernel linked list and get rid of n_hdlc.tbuf:
in case of tx error put current data buffer after the head of tx_buf_list.
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
But first update usage sites with the new header dependency.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix up affected files that include this signal functionality via sched.h.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.
Create empty placeholder header that maps to <linux/types.h>.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.
Use BUILD_BUG_ON in a couple ATM drivers.
In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement. Hopefully this patch inspires
someone else to trim vsprintf.c more.
Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix typos and add the following to the scripts/spelling.txt:
comsume||consume
comsumer||consumer
comsuming||consuming
I see some variable names with this pattern, but this commit is only
touching comment blocks to avoid unexpected impact.
Link: http://lkml.kernel.org/r/1481573103-11329-19-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now we can also jump to boot prom from sunhv console by sending
break twice on console for both running and panicked kernel
cases.
Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.
Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
show_mem() allows to filter out node specific data which is irrelevant
to the allocation request via SHOW_MEM_FILTER_NODES. The filtering is
done in skip_free_areas_node which skips all nodes which are not in the
mems_allowed of the current process. This works most of the time as
expected because the nodemask shouldn't be outside of the allocating
task but there are some exceptions. E.g. memory hotplug might want to
request allocations from outside of the allowed nodes (see
new_node_page).
Get rid of this hardcoded behavior and push the allocation mask down the
show_mem path and use it instead of cpuset_current_mems_allowed. NULL
nodemask is interpreted as cpuset_current_mems_allowed.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170117091543.25850-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is the big tty/serial driver patchset for 4.11-rc1.
Not much here, but a lot of little fixes and individual serial driver
updates all over the subsystem. Majority are for the sh-sci driver and
platform (the arch-specific changes have acks from the maintainer).
The start of the "serial bus" code is here as well, but nothing is
converted to use it yet. That work is still ongoing, hopefully will
start to show up across different subsystems for 4.12 (bluetooth is one
major place that will be used.)
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here is the big tty/serial driver patchset for 4.11-rc1.
Not much here, but a lot of little fixes and individual serial driver
updates all over the subsystem. Majority are for the sh-sci driver and
platform (the arch-specific changes have acks from the maintainer).
The start of the "serial bus" code is here as well, but nothing is
converted to use it yet. That work is still ongoing, hopefully will
start to show up across different subsystems for 4.12 (bluetooth is
one major place that will be used.)
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (109 commits)
tty: pl011: Work around QDF2400 E44 stuck BUSY bit
atmel_serial: Use the fractional divider when possible
tty: Remove extra include in HVC console tty framework
serial: exar: Enable MSI support
serial: exar: Move register defines from uapi header to consumer site
serial: pci: Remove unused pci_boards entries
serial: exar: Move Commtech adapters to 8250_exar as well
serial: exar: Fix feature control register constants
serial: exar: Fix initialization of EXAR registers for ports > 0
serial: exar: Fix mapping of port I/O resources
serial: sh-sci: fix hardware RX trigger level setting
tty/serial: atmel: ensure state is restored after suspending
serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt
serdev: ttyport: check whether tty_init_dev() fails
serial: 8250_pci: make pciserial_detach_ports() static
ARM: dts: STiH410-b2260: Enable HW flow-control
ARM: dts: STiH407-family: Use new Pinctrl groups
ARM: dts: STiH407-pinctrl: Add Pinctrl group for HW flow-control
ARM: dts: STiH410-b2260: Identify the UART RTS line
dt-bindings: serial: Update 'uart-has-rtscts' description
...
Pull locking updates from Ingo Molnar:
"The main changes in this cycle were:
- Implement wraparound-safe refcount_t and kref_t types based on
generic atomic primitives (Peter Zijlstra)
- Improve and fix the ww_mutex code (Nicolai Hähnle)
- Add self-tests to the ww_mutex code (Chris Wilson)
- Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr
Bueso)
- Micro-optimize the current-task logic all around the core kernel
(Davidlohr Bueso)
- Tidy up after recent optimizations: remove stale code and APIs,
clean up the code (Waiman Long)
- ... plus misc fixes, updates and cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
fork: Fix task_struct alignment
locking/spinlock/debug: Remove spinlock lockup detection code
lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS
lkdtm: Convert to refcount_t testing
kref: Implement 'struct kref' using refcount_t
refcount_t: Introduce a special purpose refcount type
sched/wake_q: Clarify queue reinit comment
sched/wait, rcuwait: Fix typo in comment
locking/mutex: Fix lockdep_assert_held() fail
locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock()
locking/rwsem: Reinit wake_q after use
locking/rwsem: Remove unnecessary atomic_long_t casts
jump_labels: Move header guard #endif down where it belongs
locking/atomic, kref: Implement kref_put_lock()
locking/ww_mutex: Turn off __must_check for now
locking/atomic, kref: Avoid more abuse
locking/atomic, kref: Use kref_get_unless_zero() more
locking/atomic, kref: Kill kref_sub()
locking/atomic, kref: Add kref_read()
locking/atomic, kref: Add KREF_INIT()
...
The Qualcomm Datacenter Technologies QDF2400 family of SoCs contains a
custom (non-PrimeCell) implementation of the SBSA UART. Occasionally the
BUSY bit in the Flag Register gets stuck as 1, erratum 44 for both 2432v1
and 2400v1 SoCs.Checking that the Transmit FIFO Empty (TXFE) bit is 0,
instead of checking that the BUSY bit is 1, works around the issue.
To facilitate this substitution of flags and values, introduce
vendor-specific inversion of Feature Register bits when UART AMBA Port
(UAP) data is available. For the earlycon case, prior to UAP availability,
implement alternative putc and early_write functions.
Similar to what how ARMv8 ACPI PCI quirks are detected during MCFG parsing,
check the OEM fields of the Serial Port Console Redirection (SPCR) ACPI
table to determine if the current platform is known to be affected by the
erratum.
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Timur Tabi <timur@codeaurora.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fractional baud rate generator is available when using the
asynchronous mode of Atmel USART controllers. It makes it possible to
use higher baudrates, in exchange for a less precise clock with a
variable duty cycle.
The existing code restricts its use to the normal mode of the USART
controller, following the recommendation from the datasheet for the
first chip embedding this type of controller. This recommendation has
been removed from the documentation for the newer chips. After
verification, all revisions of this controller should be able to use the
fractional baud rate generator with the different asynchronous modes.
Removing the condition on ATMEL_US_USMODE makes it possible to get
correct baudrates at high speed in more cases.
This was tested with a board using an Atmel SAMA5D2 chip and a TI
WL1831 WiFi/Bluetooth combo chip at 3 Mbauds, with hardware flow control
enabled.
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An extra "init.h" include is found in the HVC console code. As such,
the extra line is deleted.
Signed-off-by: Sergio Valverde <vlvrdv@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use pci_alloc_irq_vectors to enable MSI when available. At least the
XR17V352 supports this.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
None of these registers is relevant for the userspace API.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Became obsolete with the split-out of 8250_exar.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Those are Exar-based, too.
With the required refactoring of the code to fit into 8250_exar, we
automatically fix the same issue pci_xr17v35x_setup had before: 8XMODE,
FCTL, TXTRG and RXTRG were always only set for port 0. Now they are
initialized for the correct target port by using port.membase.
Now we can also cleanly fix the blacklist of 8250_pci so that all
Commtech devices are rejected and 8250_exar can handle them.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So far, pci_xr17v35x_setup always initialized 8XMODE, FCTR & Co. for
port 0 because it used the address of that port instead of moving the
pointer according to the port number. Fix this and remove the unneeded
temporary ioremap by moving default_setup up and reusing the membase it
fills into the port structure.
Fixes: 14faa8cce8 ("tty/8250 Add support for Commtech's Fastcom Async-335 and Fastcom Async-PCIe cards")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pcim_iomap_table only returns the table of mapping, it does not perform
them. For that, we need to call pcim_iomap, but only if that mapping was
not done before.
Fixes: d0aeaa83f0 ("serial: exar: split out the exar code from 8250_pci")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1. Do not set the RX trigger level for software timeout devices on reset;
there is no timeout by default, and data will rot.
2. Do set the RX trigger level for hardware timeout devices when set
via sysfs attribute.
Fixes SCIFA-type serial consoles.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When going to suspend, the UART registers may be lost because the power to
VDDcore is cut. This is not an issue in the normal case but when
no_console_suspend is used, we need to restore the registers in order to
get a functional console.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a Rockchip rk3399-based board during suspend/resume testing, we
found that we could get the console UART into a state where it would
print this to the console a lot:
serial8250: too much work for irq42
Followed eventually by:
NMI watchdog: BUG: soft lockup - CPU#0 stuck for 11s!
Upon debugging I found that we're in this state:
iir = 0x000000cc
lsr = 0x00000060
It appears that somehow we have a RX Timeout interrupt but there is no
actual data present to receive. When we're in this state the UART
driver claims that it handled the interrupt but it actually doesn't
really do anything. This means that we keep getting the interrupt
over and over again.
Normally we don't actually need to do anything special to handle a RX
Timeout interrupt. We'll notice that there is some data ready and
we'll read it, which will end up clearing the RX Timeout. In this
case we have a problem specifically because we got the RX TImeout
without any data. Reading a bogus byte is confirmed to get us out of
this state.
It's unclear how exactly the UART got into this state, but it is known
that the UART lines are essentially undriven and unpowered during
suspend, so possibly during resume some garbage / half transmitted
bits are seen on the line and put the UART into this state.
The UART on the rk3399 is a DesignWare based 8250 UART. From mailing
list posts, it appears that other people have run into similar
problems with DesignWare based IP. Presumably this problem is unique
to that IP, so I have placed the workaround there to avoid possibly of
accidentally triggering bad behavior on other IP. Also note the RX
Timeout behaves very differently in the DMA case, for for now the
workaround is only applied to the non-DMA case.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
My static checker complains that we don't have any error handling here.
It's simple enough to add it.
Fixes: bed35c6dfa ("serdev: add a tty port controller driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes the following sparse warning:
drivers/tty/serial/8250/8250_pci.c:3916:6: warning:
symbol 'pciserial_detach_ports' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The initial binding 'st,hw-flow-control' isn't used anywhere, in neither
in upstream nor downstream kernels. It isn't even documented in
dt-bindings, so we can safely assume it's safe to swap to the generic
one.
Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When hardware flow-control is disabled, manual toggling of the UART's
reset line (RTS) using userland applications (e.g. stty) is not
possible, since the ASC IP does not provide this functionality in the
same was as some other IPs do. Thus, we have to do this manually.
This patch ensures that when HW flow-control is disabled the RTS/CTS
lines are free to be registered via the GPIO API. It also ensures
any registered GPIO lines are unregistered when HW flow-control is
requested, allowing the IP to control them automatically.
Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are now 2 possible separate/different Pinctrl states which can
be provided from platform data. One which encompasses the lines
required for HW flow-control (CTS/RTS) and another which does not
specify these lines, such that they can be used via GPIO mechanisms
for manually toggling (i.e. from a request by `stty`).
Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Until this point, it has not been possible for userland serial
applications (e.g. stty) to toggle the UART RTS line. This can
be useful with certain configurations. For example, when using
a Mezzanine on a Linaro 96board, RTS line is used to take the
on-board microcontroller in and out of reset.
Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The datasheet states:
"If the MODE field selects an 8-bit frame then this [parity error] bit
is undefined. Software should ignore this bit when reading 8-bit frames."
Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MKS Instruments SCOM-0800 and SCOM-0801 cards (originally by Tenta
Technologies) are 3U CompactPCI serial cards with 4 and 8 serial ports,
respectively. The first 4 ports are implemented by an OX16PCI954 chip,
and the second 4 ports are implemented by an OX16C954 chip on a local
bus, bridged by the second PCI function of the OX16PCI954. The ports
are jumper-selectable as RS-232 and RS-422/485, and the UARTs use a
non-standard oscillator frequency of 20 MHz (base_baud = 1250000).
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allows tuning of the RX FIFO fill threshold and timeout. (The latter is
only applicable to SCIFA and SCIFB).
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Implements support for FIFO fill thresholds greater than one with software
timeout.
This mechanism is not possible (or at least not useful) on SCIF family
hardware other than SCIFA and SCIFB because they do not support turning off
the DR hardware timeout interrupt separately from the RI interrupt.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sets reasonable trigger defaults for the various SCIF variants.
Also corrects the FIFO size for SH7705-style ports.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Register a serdev controller with the serdev bus when a tty_port is
registered. This creates the serdev controller and create's serdev
devices for any DT child nodes of the tty_port's parent (i.e. the UART
device).
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Tested-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a serdev controller driver for tty ports.
The controller is registered with serdev when tty ports are registered
with the TTY core. As the TTY core is built-in only, this has the side
effect of making serdev built-in as well.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Tested-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serdev bus is designed for devices such as Bluetooth, WiFi, GPS
and NFC connected to UARTs on host processors. Tradionally these have
been handled with tty line disciplines, rfkill, and userspace glue such
as hciattach. This approach has many drawbacks since it doesn't fit
into the Linux driver model. Handling of sideband signals, power control
and firmware loading are the main issues.
This creates a serdev bus with controllers (i.e. host serial ports) and
attached devices. Typically, these are point to point connections, but
some devices have muxing protocols or a h/w mux is conceivable. Any
muxing is not yet supported with the serdev bus.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Tested-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a client (upward direction) operations struct for tty_port
clients. Initially supported operations are for receiving data and write
wake-up. This will allow for having clients other than an ldisc.
Convert the calls to the ldisc to use the client ops as the default
operations.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Tested-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To allow operation with a higher RX FIFO interrupt threshold in PIO
mode, it is necessary to consider the DR bit ("FIFO not full, but no
data received for 1.5 frames") as an indicator that data can be read.
Otherwise the driver will let data rot in the FIFO until the threshold
is reached.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit c7cef0a849 ("console: Add extensible console matching") added
match() method to struct console which allows the console to perform
console command line matching instead of (or in addition to) default
console matching (ie., by fixed name and index).
Commit ad1696f6f0 ("ACPI: parse SPCR and enable matching console")
introduced support for SPCR as matching console.
Commit 10879ae5f1 ("serial: pl011: add console matching function")
added the match method for pl011 console which checks for the console
string to be "pl011"
Now on a platform which has both SPCR in the ACPI tables and ttyAMA in
the command line, the ttyAMA is chosen as "selected console" but it
doesn't pass the matching console method which results in CON_CONSDEV
not being set on the "selected console".
As a result of that, the bootconsole(SPCR in the above case) is not
unregistered and all the beginning boot messages are seen twice.
This patch adds "ttyAMA" so that it's considered to match pl011 console.
Fixes: 10879ae5f1 ("serial: pl011: add console matching function")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ensure that the uart clock is enabled prior to writing to the
interrupt mask register in s3c24xx_serial_resume_noirq function.
Without enabing the uart clock, the uart register cannot be accessed.
Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the Exar specific codes from 8250_pci and blacklist those chips
so that the new Exar serial driver binds to the devices.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the serial driver for the Exar chips. And also register the
platform device for the GPIO provided by the Exar chips.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sjoerd Simons