[pwc] use of mmap

[Nicolas Boulay]

Hello,

I just try my software, i add change from a 2.6.17 kernel to a 2.6.20.
My software crash on the new kernel because size given in the mmap
allocation are now tighly check.

Before, i have done a mmap using (h*w*3)/2. h and w are the size
requested to the webcam.

But now in 2.6.20, pwc ask for abs_max size. But this size depend on
the webcam type (640*480 or 352*288). So to be clean we must set the
value according to the webcam type. But v4l is done to avoid such
specific command.

So what is the "right" way of using mmap to avoid testing the webcam
type ? (or beleive that all webcam use 640*480) ?