On 11/8/23 21:29, Greg KH wrote: > On Thu, Nov 09, 2023 at 02:12:50AM +0000, Jayant Chowdhary wrote: >> When we use an async work queue to perform the function of pumping >> usb requests to the usb controller, it is possible that amongst other >> factors, thread scheduling affects at what cadence we're able to pump >> requests. This could mean isoc usb requests miss their uframes - resulting >> in video stream flickers on the host device. >> >> To avoid this, we make the async_wq thread only produce isoc usb_requests >> with uvc buffers encoded into them. The process of queueing to the >> endpoint is done by the uvc_video_complete() handler. In case no >> usb_requests are ready with encoded information, we just queue a zero >> length request to the endpoint from the complete handler. >> >> For bulk endpoints the async_wq thread still queues usb requests to the >> endpoint. >> >> Change-Id: I8a33cbf83fb2f04376826185079f8b25404fe761 >> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx> >> Signed-off-by: Jayant Chowdhary <jchowdhary@xxxxxxxxxx> >> Suggested-by: Avichal Rakesh <arakesh@xxxxxxxxxx> >> Suggested-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> >> --- >> Based on top of >> https://lore.kernel.org/linux-usb/20230930184821.310143-1-arakesh@xxxxxxxxxx/T/#t: >> v1->v2: Added self Signed-Off-by and addressed review comments >> v2->v3: Encode to usb requests in async_wq; queue to ep in complete handler >> for isoc transfers. >> v3->v4: Address review comments around code style. >> v4->v5: Update comments. Remove 0 length request queueing from async_wq >> thread since it is already done by the complete handler. > You forgot to run checkpatch.pl :( My apologies, I sent out v6 with checkpatch.pl fixed. Thanks
