endless waiting in vidioc_dqbuf

Kenzo10099

when calling ioctl(fdCapture, VIDIOC_DQBUF, &buf) in CaptureFrame() , my program went into an endless waiting. by debugging , I found that in in video-buf.c , if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) schedule(); my program was blocked here.

Wanna know if there are some possible reasons causing this blocking.

over 16 years ago

0 Bernie Thompson TI over 16 years ago

TI__Mastermind 41665 points

One thought would be if your capture hardware was not receiving a proper clock and syncs meaning it never acknowledges receiving a new frame and so you are queued indefinitely.

0 Avneet Dhaliwal over 13 years ago in reply to Bernie Thompson TI

Prodigy 130 points

Hi Bernie,

I am facing a similar problem. Can you please elaborate more on your above explanation?

Thanks a lot.

Regards,

Avneet

0 sujit mahapatro over 13 years ago in reply to Avneet Dhaliwal

Genius 3930 points

Just a quick guess, Can you check by changing your polarity.

By the way which kernel and evm you are using.

0 Avneet Dhaliwal over 13 years ago in reply to sujit mahapatro

Prodigy 130 points

Hi Sujit,

I am a beginner in this field. I am sorry I didn't understand what you mean by "changing the polarity"??

I am using dvsdk 4.02.00.06 with linux 2.6.32 on DM368.

Regards,

Avneet

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endless waiting in vidioc_dqbuf