-----Original Message-----
From: Andrew Lunn <andrew@lunn.ch>
Sent: Thursday, February 19, 2026 7:27 AM
To: Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>
Cc: Shenwei Wang <shenwei.wang@nxp.com>; Linus Walleij
[off-list ref]; Bartosz Golaszewski [off-list ref]; Jonathan Corbet
[off-list ref]; Rob Herring [off-list ref]; Krzysztof Kozlowski
[off-list ref]; Conor Dooley [off-list ref]; Bjorn Andersson
[off-list ref]; Mathieu Poirier [off-list ref]; Frank Li
[off-list ref]; Sascha Hauer [off-list ref]; Shuah Khan
[off-list ref]; linux-gpio@vger.kernel.org; linux-
doc@vger.kernel.org; linux-kernel@vger.kernel.org; Pengutronix Kernel Team
[off-list ref]; Fabio Estevam [off-list ref]; Peng Fan
[off-list ref]; devicetree@vger.kernel.org; linux-
remoteproc@vger.kernel.org; imx@lists.linux.dev; linux-arm-
kernel@lists.infradead.org; dl-linux-imx [off-list ref]; Bartosz
Golaszewski [off-list ref]
Subject: [EXT] Re: [PATCH v8 3/4] gpio: rpmsg: add generic rpmsg GPIO driver

quoted

quoted

+   if (sync) {
+           err = wait_for_completion_timeout(&info->cmd_complete,
+                                             msecs_to_jiffies(RPMSG_TIMEOUT));
+           if (err == 0) {
+                   dev_err(&info->rpdev->dev, "rpmsg_send timeout!\n");
+                   return -ETIMEDOUT;

strange condition you return an error if err == 0, for redability use 'ret'
variable or simply:

              if(!wait_for_completion_timeout(&info->cmd_complete,
                                msecs_to_jiffies(RPMSG_TIMEOUT)) {
                      dev_err(&info->rpdev->dev, "rpmsg_send timeout!\n");
                      return -ETIMEDOUT;
              }

This will be from a comment i made. It appears that
do_wait_for_common() can return -ERESTARTSYS. I assume that should be
returned to user space?

It looks like there might be a bit of confusion around what wait_for_completion_timeout() 
actually returns. That function never returns -ERESTARTSYS. Instead, its behavior is pretty 
simple:

- 0 means the wait timed out
- A positive value means the completion happened (the value is just the remaining jiffies)

So the driver returns the timeout error, and the upper application can decide how it wants
to handle that situation, for example restart or ignore.

Thanks,
Shenwei

        Andrew