On 03/07/2015 08:52 PM, Florian Echtler wrote: > On 06.03.2015 12:47, Hans Verkuil wrote: >> On 03/06/2015 12:24 PM, Florian Echtler wrote: >>> On 21.02.2015 11:22, Hans Verkuil wrote: >>>> On 02/20/2015 10:46 PM, Florian Echtler wrote: >>>>> On 16.02.2015 12:40, Hans Verkuil wrote: >>>>>> I prefer to dig into this a little bit more, as I don't really understand >>>>>> it. Set the videobuf2-core debug level to 1 and see what the warnings are. >>>>>> Since 'buf.qbuf' fails in v4l2-compliance, it's something in the VIDIOC_QBUF >>>>>> sequence that returns an error, so you need to pinpoint that. >>>>> OK, I don't currently have access to the hardware, but I will try this >>>>> as soon as possible. >>> Finally got a chance to try again with videobuf2-core.debug=1. Same >>> result on 3.19 and 4.0-rc2, after running v4l2-compliance -s from >>> today's master (full log attached, but important part is below): >>> >>> I'm not familiar enough with the inner workings of videobuf2 to make any >>> sense of it, any new insights from you guys? >> >> Can you do: >> echo 2 >/sys/class/video4linux/videoX/dev_debug >> and run again? >> That way I see the vb2 debug messages in related to the issued ioctls. > See attachment, this is the full syslog output from one v4l2-compliance > run on 4.0-rc2, with video0/dev_debug=2 and core.debug=1. > >> And if you can also supply the v4l2-compliance -s output, just for >> reference? > Also attached for completeness, the important part is: > > Streaming ioctls: > test read/write: OK > test MMAP: OK > fail: v4l2-test-buffers.cpp(280): !g_timestamp().tv_sec && > !g_timestamp().tv_usec Hmm, I don't think I saw this before. Anyway, looking at the code I think I see at least one thing that is dubious and that needs to be changed: In sur40_process_video() you check for buffers at the start: if (list_empty(&sur40->buf_list)) return; Replace this with: if (!vb2_start_streaming_called(&sur40->queue)) return; This will wait until start_streaming was called before it starts processing video (and start_streaming is only called if at least 3 buffers have been queued). Right now the first buffer can be returned without STREAMON actually having been called. That's certainly wrong. Whether that is the cause of this bug I do not know, but fix this first. If this doesn't solve it, then please do another run but this time use echo 10 >/sys/class/video4linux/videoX/dev_debug so I see the (D)QBUF ioctls as well. Otherwise use the same procedure as before. Thanks! Hans -- 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
