REGRESSION: 2.6.28.7 => 2.6.29-rc8: pwc mmap always failes with EAGAIN

From: Markus
Date: Sat Mar 14 2009 - 12:43:17 EST


Hello!

I just tried the 2.6.29-rc8 and run into a problem.
Running motion (a motion detection software for a webcam:
http://www.lavrsen.dk/twiki/bin/view/Motion/WebHome) with the pwc
driver will give some error message:
[1] Error mapping buffer 0 mmap: Resource temporarily unavailable
[1] MAP_FAILED: Resource temporarily unavailable

Looking in the sources:
It opens the video device (/dev/video1 for me) and then tries to mmap
with:
mmap(NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED, s->fd,
buf.m.offset);

It returns MAP_FAILED and errno is EAGAIN.
>From the manpages of mmap:
"EAGAIN The file has been locked, or too much memory has been locked
(see setrlimit(2))."

The software is not able to gather a picture from the webcam (its a
logitech orbit). Everything works with kernel 2.6.28.7 and before. The
config is copied from the 2.6.28.7 (except of some new options: "make
oldconfig"). Nothing else is changed! (Only the kernel differs.)


I dont know how that can be debugged further as the pwc module wasn
changed (except of a small api-adjustment).

Thanks!

Markus

PS: Please CC me!
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