linux-stable.git/drivers/tty/serial, branch v3.14.26

serial: Fix divide-by-zero fault in uart_get_divisor()

2014-11-14T17:00:02+00:00

commit 547039ec502076e60034eeb79611df3433a99b7d upstream.

uart_get_baud_rate() will return baud == 0 if the max rate is set
to the "magic" 38400 rate and the SPD_* flags are also specified.
On the first iteration, if the current baud rate is higher than the
max, the baud rate is clamped at the max (which in the degenerate
case is 38400). On the second iteration, the now-"magic" 38400 baud
rate selects the possibly higher alternate baud rate indicated by
the SPD_* flag. Since only two loop iterations are performed, the
loop is exited, a kernel WARNING is generated and a baud rate of
0 is returned.

Reproducible with:
 setserial /dev/ttyS0 spd_hi base_baud 38400

Only perform the "magic" 38400 -> SPD_* baud transform on the first
loop iteration, which prevents the degenerate case from recognizing
the clamped baud rate as the "magic" 38400 value.

Reported-by: Robert Święcki 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: omap-serial: fix division by zero

2014-10-30T16:38:22+00:00

commit dc3187564e61260f49eceb21a4e7eb5e4428e90a upstream.

If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
calculated n values in serial_omap_is_baud_mode16() may become 0. This
causes a division by zero when calculating the difference between
calculated and desired baud rates. To prevent this, cap the n13 and n16
values on 1.

Division by zero in kernel.
[] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[] (show_stack) from [] (Ldiv0+0x8/0x10)
[] (Ldiv0) from [] (serial_omap_baud_is_mode16+0x4c/0x68)
[] (serial_omap_baud_is_mode16) from [] (serial_omap_set_termios+0x90/0x8d8)
[] (serial_omap_set_termios) from [] (uart_change_speed+0xa4/0xa8)
[] (uart_change_speed) from [] (uart_set_termios+0xa0/0x1fc)
[] (uart_set_termios) from [] (tty_set_termios+0x248/0x2c0)
[] (tty_set_termios) from [] (set_termios+0x248/0x29c)
[] (set_termios) from [] (tty_mode_ioctl+0x1c8/0x4e8)
[] (tty_mode_ioctl) from [] (tty_ioctl+0xa94/0xb18)
[] (tty_ioctl) from [] (do_vfs_ioctl+0x4a0/0x560)
[] (do_vfs_ioctl) from [] (SyS_ioctl+0x4c/0x74)
[] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x30)

Signed-off-by: Frans Klaver 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add Quark X1000 to 8250_pci.c

2014-10-15T06:36:43+00:00

commit 1ede7dcca3c4fa15a518ab0473126f9c3e621e4c upstream.

Quark X1000 contains two designware derived 8250 serial ports.
Each port has a unique PCI configuration space consisting of
BAR0:UART BAR1:DMA respectively.

Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
bitrate of up to about 2.76 megabits per second.

This patch enables standard 8250 mode

Signed-off-by: Bryan O'Donoghue 
Reviewed-by: Heikki Krogerus 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: check the result of TX buffer mapping

2014-10-05T21:52:24+00:00

commit d4089a332883ad969700aac5dd4dd5f1c4fee825 upstream.

Using dma_mapping_error() to make sure the mapping did not
fail.

Signed-off-by: Heikki Krogerus 
Cc: "Petallo, MauriceX R" 
Signed-off-by: Greg Kroah-Hartman

serial: core: Preserve termios c_cflag for console resume

2014-09-05T23:34:14+00:00

commit ae84db9661cafc63d179e1d985a2c5b841ff0ac4 upstream.

When a tty is opened for the serial console, the termios c_cflag
settings are inherited from the console line settings.
However, if the tty is subsequently closed, the termios settings
are lost. This results in a garbled console if the console is later
suspended and resumed.

Preserve the termios c_cflag for the serial console when the tty
is shutdown; this reflects the most recent line settings.

Fixes: Bugzilla #69751, 'serial console does not wake from S3'
Reported-by: Valerio Vanni 
Acked-by: Alan Cox 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

sunsab: Fix detection of BREAK on sunsab serial console

2014-08-14T01:38:26+00:00

[ Upstream commit fe418231b195c205701c0cc550a03f6c9758fd9e ]

Fix detection of BREAK on sunsab serial console: BREAK detection was only
performed when there were also serial characters received simultaneously.
To handle all BREAKs correctly, the check for BREAK and the corresponding
call to uart_handle_break() must also be done if count == 0, therefore
duplicate this code fragment and pull it out of the loop over the received
characters.

Patch applies to 3.16-rc6.

Signed-off-by: Christopher Alexander Tobias Schulze 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

serial: Fix IGNBRK handling

2014-07-09T18:18:28+00:00

commit ef8b9ddcb45fa3b1e11acd72be2398001e807d14 upstream.

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

8250_core: Fix unwanted TX chars write

2014-06-07T17:28:08+00:00

commit b08c9c317e3f7764a91d522cd031639ba42b98cc upstream.

On transmit-hold-register empty, serial8250_tx_chars
should be called only if we don't use DMA.
DMA has its own tx cycle.

Signed-off-by: Loic Poulain 
Reviewed-by: Heikki Krogerus 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Fix thread unsafe __dma_tx_complete function

2014-06-07T17:28:08+00:00

commit f8fd1b0350d3a4581125f5eda6528f5a2c5f9183 upstream.

__dma_tx_complete is not protected against concurrent
call of serial8250_tx_dma. it can lead to circular tail
index corruption or parallel call of serial_tx_dma on the
same data portion.

This patch fixes this issue by holding the port lock.

Signed-off-by: Loic Poulain 
Reviewed-by: Heikki Krogerus 
Signed-off-by: Greg Kroah-Hartman

serial: omap: Fix missing pm_runtime_resume handling by simplifying code

2014-05-31T20:20:31+00:00

commit d758c9c1b36b4d9a141c2146c70398d756167ed1 upstream.

The lack of pm_runtime_resume handling for the device state leads into
device wake-up interrupts not working after a while for runtime PM.

Also, serial-omap is confused about the use of device_may_wakeup.
The checks for device_may_wakeup should only be done for suspend and
resume, not for pm_runtime_suspend and pm_runtime_resume. The wake-up
events for PM runtime should always be enabled.

The lack of pm_runtime_resume handling leads into device wake-up
interrupts not working after a while for runtime PM.

Rather than try to patch over the issue of adding complex tests to
the pm_runtime_resume, let's fix the issues properly:

1. Make serial_omap_enable_wakeup deal with all internal PM state
   handling so we don't need to test for up->wakeups_enabled elsewhere.

   Later on once omap3 boots in device tree only mode we can also
   remove the up->wakeups_enabled flag and rely on the wake-up
   interrupt enable/disable state alone.

2. Do the device_may_wakeup checks in suspend and resume only,
   for runtime PM the wake-up events need to be always enabled.

3. Finally just call serial_omap_enable_wakeup and make sure we
   call it also in pm_runtime_resume.

4. Note that we also have to use disable_irq_nosync as serial_omap_irq
   calls pm_runtime_get_sync.

Fixes: 2a0b965cfb6e (serial: omap: Add support for optional wake-up)
Signed-off-by: Tony Lindgren 
Acked-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman