V4L2 debugging

Alyona

Hello, Texas Instruments,

My question is about how to debug errors from V4L2 ioctls.

For example, I work with V4L2 driver and my log ends with "VIDIOC_S_FMT failed : Bad address". Where should I find the place and the cause of exact error?

Thank you.

over 13 years ago

0 Prabhakar Lad over 13 years ago

Guru 11260 points

Hi,

When you call the VIDIOC_S_FMT IOCTL this the v4l2 checks if this is implemented in you driver,

if implemented it calls it or returns no tty error.

In your case when you call the above IOCTL it lands up calling vidioc_s_fmt() function. So you need to

check in your driver to which this function pointer is assigned to .vidioc_s_fmt = func() and debug this func

Thx,

--Prabhakar Lad

0 Alyona over 13 years ago in reply to Prabhakar Lad

Expert 1295 points

Thanks!

Processors

Processors forum

V4L2 debugging