Hello, On Friday, 2 November 2018 11:50:47 EET Roger Quadros wrote: > On 15/10/18 19:34, Terence Neill wrote: > > Hi Felipe, > > > > I am having some issues when attempting to stream 1280x720 uncompressed > > video @ 10fps over a USB 2.0 High-Speed link. > > > > The system setup is: > > > > WebCam --- USB 2.0 link ---> x86 Linux Machine running uvc-gadget ---- > > USB 2.0 link ---> x86 Host Machine running Windows 10. > > > > When running this setup, I am experiencing the following: > > > > 1. With streaming_maxpacket set to 2048 (2 transactions per microframe) > > the video will stream for approximately one minute before terminating > > with "VS request completed with status -18" reported in the kernel logs. > > > > 2. With streaming_maxpacket set to 3072 (3 transactions per microframe) > > the video does not stream at all with "VS request completed with status > > -18" reported in the error logs. > > There were some updates pushed recently to the uvc-gadget utility [1]. > Could you please try with that and see if this issue still persists? Thanks. > > [1] http://git.ideasonboard.org/uvc-gadget.git Worth a try, but I don't think this will make a difference. The UVC gadget function driver is known not to handle missed isoc intervals correctly. I started having a look at that, but unfortunately had to move to other projects, and I don't know when I'll have the time to get back to this issue :-/ > > From trying to analyse what is going on (looking at traces), it looks > > like the dwc3 driver is initially forwarding video buffers as expected. > > Because the bandwdith of the USB link is greater than the bandiwidth of > > the video being transmitted, at some point the dwc3 driver looks for > > more buffers to transmit and there aren't any. At this point, it seems > > to enter a state that is not recovered from whenever a new buffer > > becomes available to transmit. > > > > I have included a trace and register dump as requested for further > > analysis. > > > > In terms of hardware/software versions for the test setup: > > > > Linux machine - Intel n4200 - running Ubuntu 18.04 - kernel version > > 4.19.0-041900rc8-generic (I updated to this version this morning to make > > sure I was using the latest dwc3 driver, the same problem exists (with a > > different error code -104) with the stock Ubuntu 18.04 kernel). > > > > Windows machine - Core i5-4570 - Windows 10 Enterprise. > > > > Any help with further investigation of this problem would be appreciated? > > Could this problem be caused by the configuration setup that I'm using > > for the uvc gadget? > > > > Thanks in advance for your help, -- Regards, Laurent Pinchart
