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serial: 8250_dw: always set baud rate in dw8250_set_termios

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commit dfcab6ba573445c703235ab6c83758eec12d7f28 upstream.

dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is
NULL. This happens during resume.
Call Trace:
...
[   54.928108] dw8250_set_termios+0x162/0x170
[   54.928114] serial8250_set_termios+0x17/0x20
[   54.928117] uart_change_speed+0x64/0x160
[   54.928119] uart_resume_port
...

So the baud rate is not restored after S3 and breaks the apps who use
UART, for example, console and bluetooth etc.

We address this issue by setting the baud rate irrespective of arg
"old", just like the drivers for other 8250 IPs. This is tested with
Intel Broxton platform.

Signed-off-by: Chen Hu <hu1.chen@intel.com>
Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chen Hu 2018-07-27 18:32:41 +08:00 committed by Greg Kroah-Hartman
parent da93a03fdd
commit f6790793d8
1 changed files with 1 additions and 1 deletions
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2
drivers/tty/serial/8250/8250_dw.c
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@ -260,7 +260,7 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
long rate;
int ret;
if (IS_ERR(d->clk) || !old)
if (IS_ERR(d->clk))
goto out;
clk_disable_unprepare(d->clk);