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| author | Peter Hurley <peter@hurleysoftware.com> | 2014-06-16 08:10:41 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-19 13:04:52 -0700 |
| commit | ef8b9ddcb45fa3b1e11acd72be2398001e807d14 (patch) | |
| tree | bc3e882cdbdb0e34d1506534596be4af49e17d61 /drivers/tty/serial/mpsc.c | |
| parent | a859c8b2c309d91ba19d7bc273b41cb79b3ad17f (diff) | |
| download | talos-obmc-linux-ef8b9ddcb45fa3b1e11acd72be2398001e807d14.tar.gz talos-obmc-linux-ef8b9ddcb45fa3b1e11acd72be2398001e807d14.zip | |
serial: Fix IGNBRK handling
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 <athlon_@mail.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/mpsc.c')
| -rw-r--r-- | drivers/tty/serial/mpsc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/mpsc.c b/drivers/tty/serial/mpsc.c index e30a3ca3cea3..759c6a6fa74a 100644 --- a/drivers/tty/serial/mpsc.c +++ b/drivers/tty/serial/mpsc.c @@ -1458,7 +1458,7 @@ static void mpsc_set_termios(struct uart_port *port, struct ktermios *termios, pi->port.read_status_mask |= SDMA_DESC_CMDSTAT_PE | SDMA_DESC_CMDSTAT_FR; - if (termios->c_iflag & (BRKINT | PARMRK)) + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) pi->port.read_status_mask |= SDMA_DESC_CMDSTAT_BR; /* Characters/events to ignore */ |
