linux-toradex.git/drivers/tty/serial/mfd.c, branch v3.18.7

serial: Fix IGNBRK handling

2014-06-19T20:04:52+00:00

If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: Ivan 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

serial: mfd: Staticize local symbols

2013-10-29T23:34:11+00:00

These local symbols are used only in this file.
Fix the following sparse warnings:

drivers/tty/serial/mfd.c:296:6: warning: symbol 'hsu_dma_tx' was not declared. Should it be static?
drivers/tty/serial/mfd.c:343:6: warning: symbol 'hsu_dma_start_rx_chan' was not declared. Should it be static?
drivers/tty/serial/mfd.c:389:6: warning: symbol 'hsu_dma_rx' was not declared. Should it be static?
drivers/tty/serial/mfd.c:1186:17: warning: symbol 'serial_hsu_pops' was not declared. Should it be static?

Signed-off-by: Jingoo Han 
Signed-off-by: Greg Kroah-Hartman

serial: mfd: remove unnecessary pci_set_drvdata()

2013-09-26T22:41:38+00:00

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.

Signed-off-by: Jingoo Han 
Signed-off-by: Greg Kroah-Hartman

serial: mfd: Replace MODULE_ALIAS with MODULE_DEVICE_TABLE

2013-09-26T21:26:08+00:00

This is a PCI driver and should be auto-loaded based on PCI ID.

Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

tty: serial: mfd: drop uart_port->lock before calling tty_flip_buffer_push()

2013-08-27T23:17:34+00:00

The current driver triggers a lockdep warning for if tty_flip_buffer_push() is
called with uart_port->lock locked. This never shows up on UP kernels and comes
up only on SMP kernels.

Crash looks like this (produced with samsung.c driver):

-----
[] (unwind_backtrace+0x0/0xf8) from [] (show_stack+0x10/0x14)
[] (show_stack+0x10/0x14) from [] (dump_stack+0x6c/0xac)
[] (dump_stack+0x6c/0xac) from [] (do_raw_spin_unlock+0xc4/0xd8)
[] (do_raw_spin_unlock+0xc4/0xd8) from [] (_raw_spin_unlock_irqrestore+0xc/0)
[] (_raw_spin_unlock_irqrestore+0xc/0x38) from [] (s3c24xx_serial_rx_chars+0)
[] (s3c24xx_serial_rx_chars+0x12c/0x260) from [] (s3c64xx_serial_handle_irq+)
[] (s3c64xx_serial_handle_irq+0x48/0x60) from [] (handle_irq_event_percpu+0x)
[] (handle_irq_event_percpu+0x50/0x194) from [] (handle_irq_event+0x3c/0x5c)
[] (handle_irq_event+0x3c/0x5c) from [] (handle_fasteoi_irq+0x80/0x13c)
[] (handle_fasteoi_irq+0x80/0x13c) from [] (generic_handle_irq+0x20/0x30)
[] (generic_handle_irq+0x20/0x30) from [] (handle_IRQ+0x38/0x94)
[] (handle_IRQ+0x38/0x94) from [] (gic_handle_irq+0x34/0x68)
[] (gic_handle_irq+0x34/0x68) from [] (__irq_svc+0x40/0x70)
Exception stack(0xc04cdf70 to 0xc04cdfb8)
df60:                                     00000000 00000000 0000166e 00000000
df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000
dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff
[] (__irq_svc+0x40/0x70) from [] (arch_cpu_idle+0x28/0x30)
[] (arch_cpu_idle+0x28/0x30) from [] (cpu_startup_entry+0x5c/0x148)
[] (cpu_startup_entry+0x5c/0x148) from [] (start_kernel+0x334/0x38c)
BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360
 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: /-1, .owner_cpu: -1
CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2
Workqueue: events flush_to_ldisc
[] (unwind_backtrace+0x0/0xf8) from [] (show_stack+0x10/0x14)
[] (show_stack+0x10/0x14) from [] (dump_stack+0x6c/0xac)
[] (dump_stack+0x6c/0xac) from [] (do_raw_spin_lock+0x100/0x17c)
[] (do_raw_spin_lock+0x100/0x17c) from [] (_raw_spin_lock_irqsave+0x20/0x28)
[] (_raw_spin_lock_irqsave+0x20/0x28) from [] (uart_start+0x18/0x34)
[] (uart_start+0x18/0x34) from [] (__receive_buf+0x4b4/0x738)
[] (__receive_buf+0x4b4/0x738) from [] (n_tty_receive_buf2+0x30/0x98)
[] (n_tty_receive_buf2+0x30/0x98) from [] (flush_to_ldisc+0xec/0x138)
[] (flush_to_ldisc+0xec/0x138) from [] (process_one_work+0xfc/0x348)
[] (process_one_work+0xfc/0x348) from [] (worker_thread+0x138/0x37c)
[] (worker_thread+0x138/0x37c) from [] (kthread+0xa4/0xb0)
[] (kthread+0xa4/0xb0) from [] (ret_from_fork+0x14/0x3c)
-----

Release the port lock before calling tty_flip_buffer_push() and reacquire it
after the call.

Similar stuff was already done for few other drivers in the past, like:

commit 2389b272168ceec056ca1d8a870a97fa9c26e11a
Author: Thomas Gleixner 
Date:   Tue May 29 21:53:50 2007 +0100

    [ARM] 4417/1: Serial: Fix AMBA drivers locking

Signed-off-by: Viresh Kumar 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2013-07-03T21:35:40+00:00

Pull power management and ACPI updates from Rafael Wysocki:
"This time the total number of ACPI commits is slightly greater than
the number of cpufreq commits, but Viresh Kumar (who works on cpufreq)
remains the most active patch submitter.

To me, the most significant change is the addition of offline/online
device operations to the driver core (with the Greg's blessing) and
the related modifications of the ACPI core hotplug code. Next are the
freezer updates from Colin Cross that should make the freezing of
tasks a bit less heavy weight.

We also have a couple of regression fixes, a number of fixes for
issues that have not been identified as regressions, two new drivers
and a bunch of cleanups all over.

Highlights:

- Hotplug changes to support graceful hot-removal failures.

It sometimes is necessary to fail device hot-removal operations
gracefully if they cannot be carried out completely. For example,
if memory from a memory module being hot-removed has been allocated
for the kernel's own use and cannot be moved elsewhere, it's
desirable to fail the hot-removal operation in a graceful way
rather than to crash the kernel, but currenty a success or a kernel
crash are the only possible outcomes of an attempted memory
hot-removal. Needless to say, that is not a very attractive
alternative and it had to be addressed.

However, in order to make it work for memory, I first had to make
it work for CPUs and for this purpose I needed to modify the ACPI
processor driver. It's been split into two parts, a resident one
handling the low-level initialization/cleanup and a modular one
playing the actual driver's role (but it binds to the CPU system
device objects rather than to the ACPI device objects representing
processors). That's been sort of like a live brain surgery on a
patient who's riding a bike.

So this is a little scary, but since we found and fixed a couple of
regressions it caused to happen during the early linux-next testing
(a month ago), nobody has complained.

As a bonus we remove some duplicated ACPI hotplug code, because the
ACPI-based CPU hotplug is now going to use the common ACPI hotplug
code.

- Lighter weight freezing of tasks.

These changes from Colin Cross and Mandeep Singh Baines are
targeted at making the freezing of tasks a bit less heavy weight
operation. They reduce the number of tasks woken up every time
during the freezing, by using the observation that the freezer
simply doesn't need to wake up some of them and wait for them all
to call refrigerator(). The time needed for the freezer to decide
to report a failure is reduced too.

Also reintroduced is the check causing a lockdep warining to
trigger when try_to_freeze() is called with locks held (which is
generally unsafe and shouldn't happen).

- cpufreq updates

First off, a commit from Srivatsa S Bhat fixes a resume regression
introduced during the 3.10 cycle causing some cpufreq sysfs
attributes to return wrong values to user space after resume. The
fix is kind of fresh, but also it's pretty obvious once Srivatsa
has identified the root cause.

Second, we have a new freqdomain_cpus sysfs attribute for the
acpi-cpufreq driver to provide information previously available via
related_cpus. From Lan Tianyu.

Finally, we fix a number of issues, mostly related to the
CPUFREQ_POSTCHANGE notifier and cpufreq Kconfig options and clean
up some code. The majority of changes from Viresh Kumar with bits
from Jacob Shin, Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia,
Arnd Bergmann, and Tang Yuantian.

- ACPICA update

A usual bunch of updates from the ACPICA upstream.

During the 3.4 cycle we introduced support for ACPI 5 extended
sleep registers, but they are only supposed to be used if the
HW-reduced mode bit is set in the FADT flags and the code attempted
to use them without checking that bit. That caused suspend/resume
regressions to happen on some systems. Fix from Lv Zheng causes
those registers to be used only if the HW-reduced mode bit is set.

Apart from this some other ACPICA bugs are fixed and code cleanups
are made by Bob Moore, Tomasz Nowicki, Lv Zheng, Chao Guan, and
Zhang Rui.

- cpuidle updates

New driver for Xilinx Zynq processors is added by Michal Simek.

Multidriver support simplification, addition of some missing
kerneldoc comments and Kconfig-related fixes come from Daniel
Lezcano.

- ACPI power management updates

Changes to make suspend/resume work correctly in Xen guests from
Konrad Rzeszutek Wilk, sparse warning fix from Fengguang Wu and
cleanups and fixes of the ACPI device power state selection
routine.

- ACPI documentation updates

Some previously missing pieces of ACPI documentation are added by
Lv Zheng and Aaron Lu (hopefully, that will help people to
uderstand how the ACPI subsystem works) and one outdated doc is
updated by Hanjun Guo.

- Assorted ACPI updates

We finally nailed down the IA-64 issue that was the reason for
reverting commit 9f29ab11ddbf ("ACPI / scan: do not match drivers
against objects having scan handlers"), so we can fix it and move
the ACPI scan handler check added to the ACPI video driver back to
the core.

A mechanism for adding CMOS RTC address space handlers is
introduced by Lan Tianyu to allow some EC-related breakage to be
fixed on some systems.

A spec-compliant implementation of acpi_os_get_timer() is added by
Mika Westerberg.

The evaluation of _STA is added to do_acpi_find_child() to avoid
situations in which a pointer to a disabled device object is
returned instead of an enabled one with the same _ADR value. From
Jeff Wu.

Intel BayTrail PCH (Platform Controller Hub) support is added to
the ACPI driver for Intel Low-Power Subsystems (LPSS) and that
driver is modified to work around a couple of known BIOS issues.
Changes from Mika Westerberg and Heikki Krogerus.

The EC driver is fixed by Vasiliy Kulikov to use get_user() and
put_user() instead of dereferencing user space pointers blindly.

Code cleanups are made by Bjorn Helgaas, Nicholas Mazzuca and Toshi
Kani.

- Assorted power management updates

The "runtime idle" helper routine is changed to take the return
values of the callbacks executed by it into account and to call
rpm_suspend() if they return 0, which allows us to reduce the
overall code bloat a bit (by dropping some code that's not
necessary any more after that modification).

The runtime PM documentation is updated by Alan Stern (to reflect
the "runtime idle" behavior change).

New trace points for PM QoS are added by Sahara
().

PM QoS documentation is updated by Lan Tianyu.

Code cleanups are made and minor issues are addressed by Bernie
Thompson, Bjorn Helgaas, Julius Werner, and Shuah Khan.

- devfreq updates

New driver for the Exynos5-bus device from Abhilash Kesavan.

Minor cleanups, fixes and MAINTAINERS update from MyungJoo Ham,
Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and Wei Yongjun.

- OMAP power management updates

Adaptive Voltage Scaling (AVS) SmartReflex voltage control driver
updates from Andrii Tseglytskyi and Nishanth Menon."

* tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits)
cpufreq: Fix cpufreq regression after suspend/resume
ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()
PM / Sleep: Warn about system time after resume with pm_trace
cpufreq: don't leave stale policy pointer in cdbs->cur_policy
acpi-cpufreq: Add new sysfs attribute freqdomain_cpus
cpufreq: make sure frequency transitions are serialized
ACPI: implement acpi_os_get_timer() according the spec
ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan
ACPI: Add CMOS RTC Operation Region handler support
ACPI / processor: Drop unused variable from processor_perflib.c
cpufreq: tegra: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: s3c64xx: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: omap: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: imx6q: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: exynos: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: dbx500: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: davinci: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: arm-big-little: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: powernow-k8: call CPUFREQ_POSTCHANGE notfier in error cases
cpufreq: pcc: call CPUFREQ_POSTCHANGE notfier in error cases
...

serial: mfd: Add sysrq support

2013-06-17T19:49:43+00:00

When using MFD HSU based console, sometime we need the sysrq function
to help debugging kernel. The sysrq code is basically there, this
patch just simply enable it.

Signed-off-by: Feng Tang 
Signed-off-by: Greg Kroah-Hartman

PM / Runtime: Rework the "runtime idle" helper routine

2013-06-03T19:49:52+00:00

The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0.  If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.

Tested-by: Mika Westerberg 
Tested-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Kevin Hilman 
Reviewed-by: Ulf Hansson 
Acked-by: Alan Stern

TTY: switch tty_flip_buffer_push

2013-01-16T06:30:15+00:00

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

TTY: switch tty_insert_flip_string

2013-01-16T06:22:35+00:00

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_string this time.

Signed-off-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman