Hi Laurent, I've done the following: echo 3 >/sys/module/videobuf2_core/parameters/debug and found in /var/log/kern.log after starting my program: Apr 4 21:53:48 x240 kernel: [239432.535077] vb2: Buffer 0, plane 0 offset 0x00000000 Apr 4 21:53:48 x240 kernel: [239432.535080] vb2: Buffer 1, plane 0 offset 0x001c2000 Apr 4 21:53:48 x240 kernel: [239432.535082] vb2: Buffer 2, plane 0 offset 0x00384000 Apr 4 21:53:48 x240 kernel: [239432.535083] vb2: Allocated 3 buffers, 1 plane(s) each Apr 4 21:53:48 x240 kernel: [239432.535085] vb2: qbuf: userspace address for plane 0 changed, reacquiring memory Apr 4 21:53:48 x240 kernel: [239432.535087] vb2: qbuf: failed acquiring userspace memory for plane 0 Apr 4 21:53:48 x240 kernel: [239432.535088] vb2: qbuf: buffer preparation failed: -22 Apr 4 21:53:48 x240 kernel: [239432.535128] vb2: streamoff: not streaming Regards, Thomas ________________________________________ Von: Laurent Pinchart [laurent.pinchart@xxxxxxxxxxxxxxxx] Gesendet: Freitag, 4. April 2014 01:16 An: Scheuermann, Mail Cc: linux-media@xxxxxxxxxxxxxxx Betreff: Re: AW: v4l2_buffer with PBO mapped memory Hi Thomas, On Thursday 03 April 2014 16:52:19 Scheuermann, Mail wrote: > Hi Laurent, > > the driver my device uses is the uvcvideo. I have the kernel 3.11.0-18 from > Ubuntu 13.10 running. It is built in in a Thinkpad X240 notebook. OK. A bit of debugging will then be needed. Could you set the videobuf2-core debug parameter to 3, retry your test case and send us the kernel log ? -- Regards, Laurent Pinchart This message is subject to the following terms and conditions: MAIL DISCLAIMER<http://www.barco.com/en/maildisclaimer> -- 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
