Dear all,

I have a Dell Inspiron 1720 laptop, running Ubuntu 7.10, x86_64.  The
webcam, according to 'lsusb' is:

05a9:2640 OmniVision Technologies, Inc.

My problem is, the webcam appears to work fine for about 1 minute, and
then the picture freezes.  I have tested this using Ekiga, skype (beta
version 2.0.0.27), luvcview and gstreamer-properties.  In all
applications except Ekiga, the camera functions for about 1 minute then
the picture is frozen, until I restart the test, when the camera runs
for a further 1 minute.. ad nauseam.  With Ekiga, all tests seem to run
fine, until I attempt an actual VoIP call with a real person, when the
video and sound are garbled, and the application becomes generally
unstable, with random segfaults (see
https://bugs.launchpad.net/ubuntu/+source/ekiga/+bug/164942 ).

I have tried the latest uvcvideo driver from the SVN trunk (revision
151) but the behaviour is no different.  I have also tried various
patches that I found, with no luck (either the patches failed to apply,
or there was no difference in behaviour).

Whenever the problem occurs, I always get this in my 'dmesg' output:
[ 6045.133998] uvcvideo: Failed to resubmit video URB (-45).
[ 6045.134047] uvcvideo: Failed to resubmit video URB (-45).
[ 6045.134088] uvcvideo: Failed to resubmit video URB (-45).
[ 6045.134131] uvcvideo: Failed to resubmit video URB (-45).

I get the same diagnostics if I use 'trace=15' when loading the module -
it doesn't seem to give any more information (I use the command 'sudo
modprobe uvcvideo trace=15').  Would I need to configure
'CONFIG_USB_DEBUG=y' to get more helpful debug information?  Would I
need to recompile the Ubuntu kernel to do this?

I notice that the problem is not permanent.  In Skype, I can simply stop
and start my video to get the camera running for another minute or so.
Is there some way I could modify the driver to automatically reset the
device when this error-condition occurs?  Obviously this wouldn't be a
proper solution, but it would meet my needs.

I have tried modifying the driver, to resubmit the video URB when the
particular error-code "-45" is returned.  This does not help - it simply
fails again with the same error code.

>From looking around the 'net, it appears that -45 refers to -EL2NSYNC,
which is reportedly only used by ehci_hcd, and is perhaps audio-related.
I disabled my audio driver "snd_hda_intel", but this did not help.

Would it be helpful for me to try the 32-bit version of Ubuntu instead
of the 64-bit version?  I don't want to try this if it would be wasted
effort.

I did some searching on the "OmniVision" webcam but I could find very
little information.  By all accounts, this camera is supposed to work
perfectly with Free Software (but sadly, not for me).  It is built into
the screen of my laptop, so I really would like to get it working,
instead of just buying another cheap webcam to plug into the side.

Any help debugging this would be much appreciated.  Please let me know
what further info would be useful.

Many thanks,
Lambros


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