serial: 8250: Also set sticky MCR bits in console restoration

commit 6e6eebdf5e2455f089ccd000754a0deaeb79af82 upstream.

Sticky MCR bits are lost in console restoration if console suspending
has been disabled.  This currently affects the AFE bit, which works in
combination with RTS which we set, so we want to make sure the UART
retains control of its FIFO where previously requested.  Also specific
drivers may need other bits in the future.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend")
Cc: stable@vger.kernel.org # v4.0+
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3055353514e1dd891f3cbe5278513d77311624bb..e0fa24f0f732d8bb3c19f3334510e7b596cee888 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -3311,7 +3311,7 @@ static void serial8250_console_restore(struct uart_8250_port *up)
 
        serial8250_set_divisor(port, baud, quot, frac);
        serial_port_out(port, UART_LCR, up->lcr);
-       serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
+       serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS);
 }
 
 /*