[PATCH RESEND v2 1/8] media: uvc: Extend documentation of uvc_video_clock_decode()

From: Ricardo Ribalda
Date: Fri Dec 02 2022 - 12:03:19 EST


Make a explicit reference to uvc 1.5, explaining how the algorithm
supports the different behaviour of uvc 1.1 and 1.5.

Tested-by: HungNien Chen <hn.chen@xxxxxxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_video.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 170a008f4006..ab56e65ca324 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -517,6 +517,9 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
/*
* To limit the amount of data, drop SCRs with an SOF identical to the
* previous one.
+ * This filtering is also needed for supporting UVC 1.5. Where all the
+ * data packages of the same frame contains the same sof. In that case
+ * only the first one will match the host_sof.
*/
dev_sof = get_unaligned_le16(&data[header_size - 2]);
if (dev_sof == stream->clock.last_sof)

--
2.39.0.rc0.267.gcb52ba06e7-goog-b4-0.11.0-dev-696ae