State of Linux webcam support

John W. Linville linville at
Mon Oct 1 17:18:49 UTC 2007

On Mon, Oct 01, 2007 at 09:18:06AM -0700, Greg KH wrote:
> On Mon, Oct 01, 2007 at 11:05:38AM -0400, Ben Warren wrote:

> > Are ioctls still the preferred way to pass
> > complex data between the kernel and user space?

> For the video-for-linux interface, yes, unfortunatly they are still the
> preferred way due to a lot of legacy issues that are involved :(
> But for anything else, you are correct, use sysfs whenever possible for
> simple things, and only use an ioctl for more complex transaction-like
> things.  Although for some transaction-like things, configfs works quite
> well, you might want to look into that.

I'm not too familiar w/ v4l, so this may or may not be an appropriate
suggestion for an alternative.  But in many cases it may be worthwhile
to consider netlink (esp. the newer 'generic netlink' bits) as an
alternative configuration or even data-passing mechanism.


John W. Linville
linville at

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