Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 10 Mar 2023 11:20:54 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH v6 3/5] media: uvcvideo: Allow hw clock updates with buffers not full |
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On (23/03/09 13:55), Ricardo Ribalda wrote: [..] > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -754,10 +754,10 @@ void uvc_video_clock_update(struct uvc_streaming *stream, > > spin_lock_irqsave(&clock->lock, flags); > > - if (clock->count < clock->size) > + if (clock->count < 2) > goto done; > > - first = &clock->samples[clock->head]; > + first = &clock->samples[(clock->head - clock->count) % clock->size];
This looks like a significant change: `rb->head` and `rb->head - INT` are quite different things. May I ask for some clarifications?
[..] > + /* > + * Have at least 1/4 of a second of timestamps before we > + * try to do any calculation. Otherwise we do not have enough > + * precision. This value was determined by running Android CTS > + * on different devices. > + */ > + if ((y2 - y1) < (256 << 16))
256 << 16 is 1/4 of a second?
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