[PATCH v3 03/11] serial: sh-sci: Always set TIOCM_CTS in .get_mctrl() callback

From: Geert Uytterhoeven
Date: Fri Jun 03 2016 - 06:03:23 EST


Documentation/serial/driver clearly states:

If the port does not support CTS, DCD or DSR, the driver should
indicate that the signal is permanently active.

Hence always set TIOCM_CTS, as we currently don't look at the CTS
hardware line state at all.

FWIW, this fixes the transmit path when hardware-assisted flow control
is enabled, and userspace enables CRTSCTS.
The receive path is still broken, as RTS is never asserted.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
v3:
- Add Reviewed-by,

v2:
- Drop RFC status.
---
drivers/tty/serial/sh-sci.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 0130feb069aee02f..135f836642ab1c5a 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1835,9 +1835,9 @@ static unsigned int sci_get_mctrl(struct uart_port *port)
{
/*
* CTS/RTS is handled in hardware when supported, while nothing
- * else is wired up. Keep it simple and simply assert DSR/CAR.
+ * else is wired up. Keep it simple and simply assert CTS/DSR/CAR.
*/
- return TIOCM_DSR | TIOCM_CAR;
+ return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}

static void sci_break_ctl(struct uart_port *port, int break_state)
--
1.9.1