android_kernel_motorola_sm6375/drivers/tty
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Lukas Wunner 8f6cecfff3 serial: core: Keep mctrl register state and cached copy in sync
[ Upstream commit 93a770b7e16772530196674ffc79bb13fa927dc6 ]

struct uart_port contains a cached copy of the Modem Control signals.
It is used to skip register writes in uart_update_mctrl() if the new
signal state equals the old signal state.  It also avoids a register
read to obtain the current state of output signals.

When a uart_port is registered, uart_configure_port() changes signal
state but neglects to keep the cached copy in sync.  That may cause
a subsequent register write to be incorrectly skipped.  Fix it before
it trips somebody up.

This behavior has been present ever since the serial core was introduced
in 2002:
https://git.kernel.org/history/history/c/33c0d1b0c3eb

So far it was never an issue because the cached copy is initialized to 0
by kzalloc() and when uart_configure_port() is executed, at most DTR has
been set by uart_set_options() or sunsu_console_setup().  Therefore,
a stable designation seems unnecessary.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/bceeaba030b028ed810272d55d5fc6f3656ddddb.1641129752.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:19:46 +01:00
..
hvc xen/console: harden hvc_xen against event channel storms 2021-12-22 09:29:40 +01:00
ipwireless
serdev
serial serial: core: Keep mctrl register state and cached copy in sync 2022-01-27 09:19:46 +01:00
vt tty: Fix out-of-bound vmalloc access in imageblit 2021-10-06 15:42:29 +02:00
amiserial.c tty: amiserial: fix TIOCSSERIAL permission check 2021-05-14 09:44:10 +02:00
cyclades.c
ehv_bytechan.c
goldfish.c
isicom.c
Kconfig
Makefile
mips_ejtag_fdc.c
moxa.c tty: moxa: fix TIOCSSERIAL permission check 2021-05-14 09:44:11 +02:00
moxa.h
mxser.c
mxser.h
n_gsm.c
n_hdlc.c
n_null.c
n_r3964.c
n_tracerouter.c
n_tracesink.c
n_tracesink.h
n_tty.c
nozomi.c tty: nozomi: Fix the error handling path of 'nozomi_card_init()' 2021-07-14 16:53:41 +02:00
pty.c
rocket.c
rocket.h
rocket_int.h
synclink.c
synclink_gt.c tty: synclink_gt: rename a conflicting function name 2021-09-30 10:09:23 +02:00
synclinkmp.c
sysrq.c
tty_audit.c
tty_baudrate.c
tty_buffer.c tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc 2021-11-26 10:47:16 +01:00
tty_io.c tty: Fix data race between tiocsti() and flush_to_ldisc() 2021-09-15 09:47:39 +02:00
tty_ioctl.c
tty_jobctrl.c
tty_ldisc.c
tty_ldsem.c
tty_mutex.c
tty_port.c
ttynull.c
vcc.c