diff mbox

[v2,03/11] serial: sh-sci: Always set TIOCM_CTS in .get_mctrl() callback

Message ID 1461934714-18681-4-git-send-email-geert+renesas@glider.be (mailing list archive)
State New, archived
Headers show

Commit Message

Geert Uytterhoeven April 29, 2016, 12:58 p.m. UTC
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@glider.be>
---
v2:
  - Drop RFC status.
---
 drivers/tty/serial/sh-sci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Peter Hurley April 29, 2016, 3:38 p.m. UTC | #1
On 04/29/2016 05:58 AM, Geert Uytterhoeven wrote:
> 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.

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>

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diff mbox

Patch

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)