linux.git/drivers/tty, branch v3.16-rc2

Merge tag 'tty-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2014-06-21T16:41:42+00:00

Pull tty/serial bugfixes from Greg KH:
 "Here are some tty / serial driver bugfixes for 3.16-rc2 that resolve
  some reported issues.  The samsung driver build error itself has been
  reported by a bunch of people, sorry about that one.  The others are
  all tiny and everyone seems to like them in linux-next so far"

* tag 'tty-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty/serial: fix 8250 early console option passing to regular console
  tty: Correct INPCK handling
  serial: Fix IGNBRK handling
  serial: samsung: Fix build error

tty/serial: fix 8250 early console option passing to regular console

2014-06-19T20:07:26+00:00

In the conversion to generic early console, the passing of options from
the early 8250 console to the regular ttyS console was broken. This
resulted in the baud rate changing when switching consoles during boot.

This feature allows specifying a single console option on the kernel
command line rather than both an early console and regular serial tty
console. It would be nice to generalize this feature. However, it only
works if the correct baud rate can be probed early which is not the
case on many platforms which have non-standard UART clock rates. So for
now, this is left as an 8250 specific feature.

Reported-and-tested-by: Tony Luck 
Signed-off-by: Rob Herring 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

tty: Correct INPCK handling

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

If INPCK is not set, input parity detection should be disabled. This means
parity errors should not be received from the tty driver, and the data
received should be treated normally.

SUS v3, 11.2.2, General Terminal Interface - Input Modes, states:
  "If INPCK is set, input parity checking shall be enabled. If INPCK is
   not set, input parity checking shall be disabled, allowing output parity
   generation without input parity errors. Note that whether input parity
   checking is enabled or disabled is independent of whether parity detection
   is enabled or disabled (see Control Modes). If parity detection is enabled
   but input parity checking is disabled, the hardware to which the terminal
   is connected shall recognize the parity bit, but the terminal special file
   shall not check whether or not this bit is correctly set."

Ignore parity errors reported by the tty driver when INPCK is not set, and
handle the received data normally.

Fixes: Bugzilla #71681, 'Improvement of n_tty_receive_parity_error from n_tty.c'
Reported-by: Ivan 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

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

Merge tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel into drm-next

2014-06-19T00:54:35+00:00

First round of fixes for 3.16-rc, mostly cc: stable, and the vt/vgacon
fixes from Daniel [1] to avoid hangs and unclaimed register errors on
module load/reload.

* tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel:
  drm/i915/bdw: remove erroneous chv specific workarounds from bdw code
  drm/i915: fix possible refcount leak when resetting forcewake
  drm/i915: Reorder semaphore deadlock check
  drm/i95: Initialize active ring->pid to -1
  drm/i915: set backlight duty cycle after backlight enable for gen4
  drm/i915: Avoid div-by-zero when pixel_multiplier is zero
  drm/i915: Disable FBC by default also on Haswell and later
  drm/i915: Kick out vga console
  drm/i915: Fixup global gtt cleanup
  vt: Don't ignore unbind errors in vt_unbind
  vt: Fix up unregistration of vt drivers
  vt: Fix replacement console check when unbinding

serial: samsung: Fix build error

2014-06-18T00:09:36+00:00

Fixes the following build error due to a typo introduced
by commit e4ac92df27 ("serial: samsung: Neaten dbg uses"):
drivers/tty/serial/samsung.c:69:26: error: ‘buf’ undeclared (first use in this function)

Reported-by: Arun Kumar K 
Signed-off-by: Sachin Kamat 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Christian Engelmayer 
Acked-by: Joe Perches 
Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

2014-06-11T23:50:01+00:00

Pull arch/tile changes from Chris Metcalf:
 "These mostly just address smaller issues reported to me"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch: tile: kernel: unaligned.c: Cleaning up uninitialized variables
  drivers/tty/hvc/hvc_tile.c: use PTR_ERR_OR_ZERO
  replace strict_strto* call with kstrto*
  tile: Update comments for generic idle conversion
  tile: cleanup the comment in init_pgprot
  tile: use BOOTMEM_DEFAULT instead of magic number 0 for reserve_bootmem flags

Merge branch 'next' (accumulated 3.16 merge window patches) into master

2014-06-08T18:31:16+00:00

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

sysrq,rcu: suppress RCU stall warnings while sysrq runs

2014-06-06T23:08:17+00:00

Some sysrq handlers can run for a long time, because they dump a lot of
data onto a serial console.  Having RCU stall warnings pop up in the
middle of them only makes the problem worse.

This patch temporarily disables RCU stall warnings while a sysrq request
is handled.

Signed-off-by: Rik van Riel 
Suggested-by: Paul McKenney 
Signed-off-by: Paul E. McKenney 
Cc: Madper Xie 
Cc: Randy Dunlap 
Cc: Richard Weinberger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysrq: rcu-ify __handle_sysrq

2014-06-06T23:08:17+00:00

Echoing values into /proc/sysrq-trigger seems to be a popular way to get
information out of the kernel.  However, dumping information about
thousands of processes, or hundreds of CPUs to serial console can result
in IRQs being blocked for minutes, resulting in various kinds of cascade
failures.

The most common failure is due to interrupts being blocked for a very
long time.  This can lead to things like failed IO requests, and other
things the system cannot easily recover from.

This problem is easily fixable by making __handle_sysrq use RCU instead
of spin_lock_irqsave.

This leaves the warning that RCU grace periods have not elapsed for a
long time, but the system will come back from that automatically.

It also leaves sysrq-from-irq-context when the sysrq keys are pressed,
but that is probably desired since people want that to work in
situations where the system is already hosed.

The callers of register_sysrq_key and unregister_sysrq_key appear to be
capable of sleeping.

Signed-off-by: Rik van Riel 
Reported-by: Madper Xie 
Cc: Randy Dunlap 
Cc: Richard Weinberger 
Cc: Paul E. McKenney 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds