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>

diff --cc drivers/tty/serial/8250/8250_core.c
Simple merge

diff --cc drivers/tty/serial/altera_uart.c
Simple merge

diff --cc drivers/tty/serial/amba-pl010.c
Simple merge

diff --cc drivers/tty/serial/amba-pl011.c
Simple merge

diff --cc drivers/tty/serial/atmel_serial.c
Simple merge

diff --cc drivers/tty/serial/bcm63xx_uart.c
Simple merge

diff --cc drivers/tty/serial/bfin_uart.c
Simple merge

diff --cc drivers/tty/serial/dz.c
Simple merge

diff --cc drivers/tty/serial/efm32-uart.c
Simple merge

diff --cc drivers/tty/serial/fsl_lpuart.c
Simple merge

diff --cc drivers/tty/serial/ip22zilog.c
Simple merge

diff --cc drivers/tty/serial/m32r_sio.c
Simple merge

diff --cc drivers/tty/serial/max310x.c
Simple merge

diff --cc drivers/tty/serial/mcf.c
Simple merge

diff --cc drivers/tty/serial/mfd.c
Simple merge

diff --cc drivers/tty/serial/mpsc.c
Simple merge

diff --cc drivers/tty/serial/msm_serial.c
Simple merge

diff --cc drivers/tty/serial/mxs-auart.c
Simple merge

diff --cc drivers/tty/serial/netx-serial.c
Simple merge

diff --cc drivers/tty/serial/pmac_zilog.c
Simple merge

diff --cc drivers/tty/serial/pnx8xxx_uart.c
Simple merge

diff --cc drivers/tty/serial/pxa.c
Simple merge

diff --cc drivers/tty/serial/sb1250-duart.c
Simple merge

diff --cc drivers/tty/serial/sccnxp.c
Simple merge

diff --cc drivers/tty/serial/serial_ks8695.c
Simple merge

diff --cc drivers/tty/serial/serial_txx9.c
Simple merge

diff --cc drivers/tty/serial/sirfsoc_uart.c
Simple merge

diff --cc drivers/tty/serial/st-asc.c
Simple merge

diff --cc drivers/tty/serial/sunsab.c
Simple merge

diff --cc drivers/tty/serial/sunsu.c
Simple merge

diff --cc drivers/tty/serial/sunzilog.c
Simple merge

diff --cc drivers/tty/serial/ucc_uart.c
Simple merge

diff --cc drivers/tty/serial/vr41xx_siu.c
Simple merge

diff --cc drivers/tty/serial/zs.c
Simple merge