Re: [PATCH 1/6] USB: serial: cp210x: fix control-characters error handling

On Fri, Jul 02, 2021 at 04:47:11PM +0200, Greg Kroah-Hartman wrote:

On Fri, Jul 02, 2021 at 03:42:22PM +0200, Johan Hovold wrote:

quoted

In the unlikely event that setting the software flow-control characters
fails the other flow-control settings should still be updated.

Fixes: 7748feffcd80 ("USB: serial: cp210x: add support for software flow control")
Cc: stable@vger.kernel.org	# 5.11
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/cp210x.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 09b845d0da41..b41e2c7649fb 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c

@@ -1217,9 +1217,7 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
 		chars.bXonChar = START_CHAR(tty);
 		chars.bXoffChar = STOP_CHAR(tty);
 
-		ret = cp210x_set_chars(port, &chars);
-		if (ret)
-			return;
+		cp210x_set_chars(port, &chars);

What's the odds that someone tries to add the error checking back in
here, in a few years?  Can you put a comment here saying why you are not
checking it?

This is just how set_termios() works and how the other requests are
handled by the driver. I can add an explicit error message here though
just like when setting the line-control register so that it doesn't look
like an oversight. The error message is currently printed by the
set_chars() helper, but I can move that out when removing the helper
later in the series.

Johan