Re: [question] v4l read() operation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]



Hi Dave,

2012/2/25 Dave Hylands <dhylands@xxxxxxxxx>:
>
> I'm not all that familiar with v4l, but based on what you've posted,
> you need to populate the read routine in your v4l2_fops structure to
> support read.
>

My bad! You are totally right: I forgot about my webcam.
When I did:

$ cat /dev/video0

I was actually getting data from my webcam (which supports read),
and not from the easycap device, which is /dev/video1.

So, everything makes sense now:

$ cat /dev/video1

...
open("/dev/video1", O_RDONLY|O_LARGEFILE) = 3
...
read(3, 0x8835000, 32768)               = -1 EINVAL (Invalid argument)

This is clearly shown by the piece of code mentioned before.

Thanks and sorry for the noise,
Ezequiel.

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


[Newbies FAQ]     [Linux Kernel Mentors]     [Linux Kernel Development]     [IETF Annouce]     [Git]     [Networking]     [Security]     [Bugtraq]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Networking]     [Linux RAID]     [Linux SCSI]     [Linux ACPI]

Add to Google Powered by Linux