On Tue, Aug 09, 2016 at 01:02:31AM +0200, Piotr Król wrote: > On Sat, Aug 06, 2016 at 04:00:22PM +0200, Piotr Król wrote: > > Hi all, > > Hi Hans, Igor, +Igor > I found your discussion about very similar issue here [5]. It looks > like musb driver in host mode doesn't give enough bandwidth for USB > camera in my case. > > We tested USB device and getting not so bad results for bulk endpoint > read (15MB/s) and write (1.8MB/s). I'm not sure, if this numbers make > sense for isochronous endpoint, but it seems there is enough bandwidth > for video data transfer. > > Full dmesg can be found here [6] > > Have you got any ideas what maybe wrong ? Does it make sense to use musb > in host mode to transfer video stream ? > > Any help appreciated. > > > We have custom Allwinner A20 based hardware on which we try to utilize > > USB DRD (configured in device tree as host [1]) to connect Creative web > > camera [2]. > > > > We use 4.7 kernel release built using buildroot. Hardware configuration can > > be described like that: > > > > A20 mainboard -> LAN9514i -> Creative web camera > > > > I tried v4l2grab and fswebcam, but both application result in > > "uvcvideo: Failed to submit URB 0 (-28)" and further complaining that > > there is no space left on device, despite there is planty of free > > space [3]. We also tried to capture in /tmp with the same result. > > > > v4l2grab output: > > # v4l2grab -d /dev/video0 -o image.jpg > > [ 1802.800160 ] uvcvideo: Failed to submit URB 0 (-28). > > libv4l2: error turning on stream: No space left on device > > VIDIOC_STREAMON error 28, No space left on device > > > > fswebcam output: > > # fswebcam -r 1280x720 --jpeg 95 -D 1 image.jpg > > --- Opening /dev/video0... > > Trying source module v4l2... > > /dev/video0 opened. > > No input was specified, using the first. > > Delaying 1 seconds. > > [ 432.952080 ] uvcvideo: Failed to submit URB 0 (-28). > > Error starting stream. > > VIDIOC_STREAMON: No space left on device > > Unable to use mmap. Using read instead. > > Unable to use read. > > > > What we also tried is checking camera with Raspberry Pi Compute Module > > in that way: > > > > RPICM -> LAN9514i -> LAN9514i -> Creative web camera > > > > And this works without problem. > > > > We proved that USB was correctly configured in host mode by trying > > usb-storage, usbhid and ftdi driver, what can be found in dmesg [4]. > > > > I have hard time with finding from what code -28 came from, since calls > > are nested in usb subsystem. What this error means ? How it can be > > avoided ? > > > > Any other ideas how to debug this issue further are welcome. > > > > [1] http://paste.ubuntu.com/22446905/ > > [2] http://www.scanmalta.com/scanshop/creative-live-cam-sync-1-3mp-hd-webcam.html > > [3] http://paste.ubuntu.com/22448114/ > > [4] http://paste.ubuntu.com/22446585/ > > [5] https://groups.google.com/d/msg/linux-sunxi/-O3GckFuje8/aTAkPk1JCQAJ > [6] http://paste.ubuntu.com/22747309/ > > > > -- > > Best Regards, > > Piotr Król > > Embedded Systems Consultant > > http://3mdeb.com | @3mdeb_com > > -- > Best Regards, > Piotr Król > Embedded Systems Consultant > http://3mdeb.com | @3mdeb_com -- Best Regards, Piotr Król Embedded Systems Consultant http://3mdeb.com | @3mdeb_com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
