From: Markus <M4rkusXXL@web.de>
To: lkml <linux-kernel@vger.kernel.org>
Subject: REGRESSION: 2.6.28.7 => 2.6.29-rc8: pwc mmap always failes with EAGAIN
Date: Sat, 14 Mar 2009 17:42:53 +0100
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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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