serial: sc16is7xx: Clear RS485 bits in the shutdown
authorHui Wang <hui.wang@canonical.com>
Tue, 8 Mar 2022 11:00:42 +0000 (19:00 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 18 Mar 2022 12:25:09 +0000 (13:25 +0100)
commit927728a34f11b5a27f4610bdb7068317d6fdc72a
tree82a3465ca26852e2964fbeb1ef99031741f2855f
parentf25fbd5b1ef3773bd975135f8a017dc2251626cc
serial: sc16is7xx: Clear RS485 bits in the shutdown

We tested RS485 function on an EVB which has SC16IS752, after
finishing the test, we started the RS232 function test, but found the
RTS is still working in the RS485 mode.

That is because both startup and shutdown call port_update() to set
the EFCR_REG, this will not clear the RS485 bits once the bits are set
in the reconf_rs485(). To fix it, clear the RS485 bits in shutdown.

Cc: <stable@vger.kernel.org>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20220308110042.108451-1-hui.wang@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/sc16is7xx.c