[PATCH 4.9 18/25] serial: omap: Fix EFR write on RTS deassertion

Greg Kroah-Hartman
2017-11-22T10:14:34Z

From: Lukas Wunner <lukas@wunner.de>

commit 2a71de2f7366fb1aec632116d0549ec56d6a3940 upstream.

Commit 348f9bb31c56 ("serial: omap: Fix RTS handling") sought to enable
auto RTS upon manual RTS assertion and disable it on deassertion.
However it seems the latter was done incorrectly, it clears all bits in
the Extended Features Register *except* auto RTS.

Fixes: 348f9bb31c56 ("serial: omap: Fix RTS handling")
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/tty/serial/omap-serial.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -693,7 +693,7 @@ static void serial_omap_set_mctrl(struct
if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
up->efr |= UART_EFR_RTS;
else
- up->efr &= UART_EFR_RTS;
+ up->efr &= ~UART_EFR_RTS;
serial_out(up, UART_EFR, up->efr);
serial_out(up, UART_LCR, lcr);