i.MX ProcessorsのトピックRe: IMX6 VIDIOC_DQBUF failed issue

IMX6 VIDIOC_DQBUF failed issue

umit_kayacik — Tue, 08 Oct 2019 11:17:40 GMT

Hi,

While tring below commands my v4l driver generates below error.

./mxc_v4l2_tvin.out -ow 720 -oh 480 -ot 20 -ol 20 -c 10 -m 0 -tb -f YUYV

ERROR: v4l2 capture: mxc_v4l_dqueue timeout enc_counter 0
VIDIOC_DQBUF failed.

What can be the possible root causes for this issue?

Cheers

Re: IMX6 VIDIOC_DQBUF failed issue

umit_kayacik — Wed, 09 Oct 2019 06:01:27 GMT

How can i debug this issue?

Re: IMX6 VIDIOC_DQBUF failed issue

Bio_TICFSL — Wed, 09 Oct 2019 16:00:45 GMT

Hello Umit,

This error is V4L2 Capture IOCTLs error, described for example at

VIDIOC_DQBUF: Resource temporarily unavailable · Issue #3 · fsphil/fswebcam · GitHub

Regards

Re: IMX6 VIDIOC_DQBUF failed issue

umit_kayacik — Fri, 11 Oct 2019 04:38:34 GMT

Hi,

I found an application note and it points to check below registers.

How can i check them in yocto? Is there any specific tool besides debugger cause i dont have.

5.2 No video issue

---------------------------
Mxc_v4l2_tvin application reports timeout and exit, the error messages like “ERROR: v4l2 capture:
mxc_v4l_dqueue timeout enc_counter0 VIDIOC_DQBUF failed”. This means the v4l2 capture driver hasn’t
captured valid video frame.
The followed things can be checked:
Is CSI_DATA_EN pin been enabled by software but pulled down?
Is there valid pixel clock?
Is there EAV/SAV embedded on data line?
Adjust the drive strength of the BT.656 pins.
Is the frame size set in IPU_CSI_SENS_FRM_SIZE register bigger than the real frame size?
Is the frame size set in IPU_CSI_ACT_FRM_SIZE register bigger than the real frame size?
Is the IOMUX_GPR1 for iMX6DQ or IOMUX_GPIO13 for iMX6SDL been correctly set?
To avoid hardware issue, the customer can set the data and clock pins as GPIO and output 0/1,
then measure if each PIN can work correctly.

Regards