[PATCH v5 0/2] media: uvcvideo: Support partial control reads and minor changes

From: Ricardo Ribalda
Date: Thu Nov 28 2024 - 15:54:39 EST


Some cameras do not return all the bytes requested from a control
if it can fit in less bytes. Eg: returning 0xab instead of 0x00ab.
Support these devices.

Also, now that we are at it, improve uvc_query_ctrl() logging.

Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
Changes in v5:
- Improve comment.
- Link to v4: https://lore.kernel.org/r/20241120-uvc-readless-v4-0-4672dbef3d46@xxxxxxxxxxxx

Changes in v4:
- Improve comment.
- Keep old likely(ret == size)
- Link to v3: https://lore.kernel.org/r/20241118-uvc-readless-v3-0-d97c1a3084d0@xxxxxxxxxxxx

Changes in v3:
- Improve documentation.
- Do not change return sequence.
- Use dev_ratelimit and dev_warn_once
- Link to v2: https://lore.kernel.org/r/20241008-uvc-readless-v2-0-04d9d51aee56@xxxxxxxxxxxx

Changes in v2:
- Rewrite error handling (Thanks Sakari)
- Discard 2/3. It is not needed after rewriting the error handling.
- Link to v1: https://lore.kernel.org/r/20241008-uvc-readless-v1-0-042ac4581f44@xxxxxxxxxxxx

---
Ricardo Ribalda (2):
media: uvcvideo: Support partial control reads
media: uvcvideo: Add more logging to uvc_query_ctrl()

drivers/media/usb/uvc/uvc_video.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
---
base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
change-id: 20241008-uvc-readless-23f9b8cad0b3

Best regards,
--
Ricardo Ribalda <ribalda@xxxxxxxxxxxx>