Hi Michael, Quoting Michael Grzeschik (2024-02-06 21:30:17) > On Tue, Feb 06, 2024 at 03:23:17AM +0000, Thinh Nguyen wrote: > >On Tue, Feb 06, 2024, Michael Grzeschik wrote: > >> Hi Thinh > >> > >> I found some strange situation while streaming via uvc-gadget to some > >> usb host. It happens when some requests are missed due to higher load on > >> the gadget machine. In some cases some requests will reach the host > >> twice. In my special case, I added the following changes [1] for the > >> host and gadget side. > > > >Does this only happen to some specific hosts? > > >Are all the data of the duplicate requests matching or just some bits of > >the transfer? Were you able to confirm from some usb analyzer/sniffer > >that the data out the wire is actually duplicate? > > Turns out, this duplicates are just misinterpretations. I'm glad there's no deeper issue to worry about here. > The linux uvcvideo driver will parse the uvc header payload twice. (If > the FID was incremented inbetween). This led to those double misleading > outputs. Although this means that there is a bug in > uvc_video_stats_decode for incrementing the error count. Do you plan/are you able to submit a patch to fix this? Hopefully that would prevent anyone else following the same rabbit-hole. -- Kieran > > Anyway, so just ignore this whole thread and be thanked for even having any > thoghts on this. > > Regards, > Michael > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
