| Message ID | 20241008-uvc-readless-v1-1-042ac4581f44@chromium.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | media: uvcvideo: Support partial control reads and minor changes | expand |
Hi Ricardo, On Tue, Oct 08, 2024 at 07:06:14AM +0000, Ricardo Ribalda wrote: > Some cameras, like the ELMO MX-P3, do not return all the bytes > requested from a control if it can fit in less bytes. > Eg: Returning 0xab instead of 0x00ab. > usb 3-9: Failed to query (GET_DEF) UVC control 3 on unit 2: 1 (exp. 2). > > Extend the returned value from the camera and return it. > > Cc: stable@vger.kernel.org > Fixes: a763b9fb58be ("media: uvcvideo: Do not return positive errors in uvc_query_ctrl()") Is this really the patch that introduced the problem? > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > --- > drivers/media/usb/uvc/uvc_video.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index cd9c29532fb0..853dfb7b5f7b 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -79,11 +79,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, > if (likely(ret == size)) > return 0; > > + if (ret > 0 && ret < size) { > + memset(data + ret, 0, size - ret); It'd be nice to have a comment in the code why this is being done (including it's little endian). > + return 0; > + } > + > if (ret != -EPIPE) { > dev_err(&dev->udev->dev, > "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", > uvc_query_name(query), cs, unit, ret, size); > - return ret < 0 ? ret : -EPIPE; > + return ret ? ret : -EPIPE; > } > > /* Reuse data[0] to request the error code. */ >
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index cd9c29532fb0..853dfb7b5f7b 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -79,11 +79,16 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, if (likely(ret == size)) return 0; + if (ret > 0 && ret < size) { + memset(data + ret, 0, size - ret); + return 0; + } + if (ret != -EPIPE) { dev_err(&dev->udev->dev, "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", uvc_query_name(query), cs, unit, ret, size); - return ret < 0 ? ret : -EPIPE; + return ret ? ret : -EPIPE; } /* Reuse data[0] to request the error code. */
Some cameras, like the ELMO MX-P3, do not return all the bytes requested from a control if it can fit in less bytes. Eg: Returning 0xab instead of 0x00ab. usb 3-9: Failed to query (GET_DEF) UVC control 3 on unit 2: 1 (exp. 2). Extend the returned value from the camera and return it. Cc: stable@vger.kernel.org Fixes: a763b9fb58be ("media: uvcvideo: Do not return positive errors in uvc_query_ctrl()") Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> --- drivers/media/usb/uvc/uvc_video.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)