Hi Ricardo,
Thank you for the patch.
On Wed, Jan 29, 2025 at 12:39:46PM +0000, Ricardo Ribalda wrote:
> uvc_gpio_parse() can return -EPROBE_DEFER when the GPIOs it depends on
> have not yet been probed. This return code should be propagated to the
> caller of uvc_probe() to ensure that probing is retried when the required
> GPIOs become available.
>
> Currently, this error code is incorrectly converted to -ENODEV,
> causing some internal cameras to be ignored.
>
> This commit fixes this issue by propagating the -EPROBE_DEFER error.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 2886477ff987 ("media: uvcvideo: Implement UVC_EXT_GPIO_UNIT")
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_driver.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index a10d4f4d9f95..73a7f23b616c 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -2253,9 +2253,10 @@ static int uvc_probe(struct usb_interface *intf,
> }
>
> /* Parse the associated GPIOs. */
> - if (uvc_gpio_parse(dev) < 0) {
> + ret = uvc_gpio_parse(dev);
> + if (ret < 0) {
> uvc_dbg(dev, PROBE, "Unable to parse UVC GPIOs\n");
> - goto error;
> + goto error_retcode;
> }
>
> dev_info(&dev->udev->dev, "Found UVC %u.%02x device %s (%04x:%04x)\n",
> @@ -2328,9 +2329,11 @@ static int uvc_probe(struct usb_interface *intf,
> return 0;
>
> error:
> + ret = -ENODEV;
> +error_retcode:
This isn't very nice. Could we instead also propagate error codes from
other locations in the uvc_probe() function ? If you want to minimize
changes, you can initialize ret to -ENODEV, and turn the (ret < 0) check
for uvc_gpio_parse() to a (ret) check.
> uvc_unregister_video(dev);
> kref_put(&dev->ref, uvc_delete);
> - return -ENODEV;
> + return ret;
> }
>
> static void uvc_disconnect(struct usb_interface *intf)
>
> ---
> base-commit: c4b7779abc6633677e6edb79e2809f4f61fde157
> change-id: 20250129-uvc-eprobedefer-b5ebb4db63cc
--
Regards,
Laurent Pinchart
