serial: sh-sci: Fix late enablement of AUTORTS
authorGeert Uytterhoeven <geert+renesas@glider.be>
Tue, 28 Mar 2017 09:13:45 +0000 (11:13 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 31 Mar 2017 13:29:05 +0000 (15:29 +0200)
commit5f76895e4c712b1b5af450cf344389b8c53ac2c2
treeb1d427346047aa90b6e84c1305d136986ddce570
parente37f712f760478a3bce8a68b8d85b5b0bf6642eb
serial: sh-sci: Fix late enablement of AUTORTS

When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised.  However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.

To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).

Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc253854cf ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/sh-sci.c