Hi,
On Wed, Jan 29, 2025 at 4:40 AM Ricardo Ribalda ribalda@chromium.org 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@vger.kernel.org Fixes: 2886477ff987 ("media: uvcvideo: Implement UVC_EXT_GPIO_UNIT") Signed-off-by: Ricardo Ribalda ribalda@chromium.org
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;
FWIW, since you're specifically considering the -EPROBE_DEFER case, it's probably worthwhile to make sure that dev_err_probe() is called. That eventually calls device_set_deferred_probe_reason() which can be helpful for tracking down problems.
It looks like uvc_gpio_parse() already calls this if gpiod_to_irq() returns an error code probably you also want to make sure that dev_err_probe() also gets called in the case where devm_gpiod_get_optional() returns -EPROBE_DEFER. In that case, potentially one could also get rid of the uvc_dbg() above.
In any case, IMO even without those changes your patch is still worth landing. ...and maybe my suggestion should be in a separate follow-on patch anyway. Thus:
Reviewed-by: Douglas Anderson dianders@chromium.org