serial: max310x: don't clobber the TX break bit in set_termios

A TX break asserted with TIOCSBRK ends early, with no error reported,
as soon as any termios change lands on the port: a break is a state
that must hold until TIOCCBRK, but max310x_set_termios() overwrites
the whole LCR register, and LCR also carries the TX break bit that
break_ctl() drives. No concurrency is required - a baud or parity
change from the same process ends the break just as well, and
break-led protocols lose their break with nothing in the logs.

Update only the LCR bits that are derived from termios and leave the
TX break and RTS pin control bits untouched. Since nothing clears a
break when a port is closed with the break still asserted - the tty
core sends no break-off on release, and the unconditional write here
was the accidental recovery - clear TXBREAK in startup(), the same way
8250 does.

Fixes: f65444187a66 ("serial: New serial driver MAX310X")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Tapio Reijonen <tapio.reijonen@vaisala.com>
Link: https://patch.msgid.link/20261008-max310x-rs485-sw-delay-v8-1-6ba881f81e1f@vaisala.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions