Hi,
[ 136.724786] uvcvideo: Found reference to unknown entity 6.
[ 136.724787] uvcvideo: No valid video chain found.
This causes the driver initialization process to fail.
You can test by replacing in uvc_driver.c, the following lines in
function uvc_scan_chain:
----//------
/* Process entity */
if (uvc_scan_chain_entity(chain, entity) < 0)
return -EINVAL;
/* Forward scan */
if (uvc_scan_chain_forward(chain, entity, prev) < 0)
return -EINVAL;
/* Backward scan */
prev = entity;
if (uvc_scan_chain_backward(chain, &entity) < 0)
return -EINVAL;
----//-----
by
----//-----
/* Process entity */
if (uvc_scan_chain_entity(chain, entity) < 0)
{
uvc_trace(UVC_TRACE_DESCR, "uvc_scan_chain_entity failed\n");
continue;
}
/* Forward scan */
if (uvc_scan_chain_forward(chain, entity, prev) < 0)
{
uvc_trace(UVC_TRACE_DESCR, "uvc_scan_chain_forward failed\n");
continue;
}
/* Backward scan */
prev = entity;
if (uvc_scan_chain_backward(chain, &entity) < 0)
{
uvc_trace(UVC_TRACE_DESCR, "uvc_scan_chain_backward failed\n");
continue;
}
----//----
Hi Paulo. Thanks for the help.
I did as you suggested. The problem still occurs. I added some __LINE__
trace logs to navigate, but there is a lot more information when running the
uvcvideo modules with trace logging ( modprobe uvcvideo trace=65535 ). I've
attached a new dmesg.log
This is my first time venturing into kernel module code so I am pretty
lost...
Post by Paulo AssisHi,
[ 8.852232] uvcvideo: Found UVC 1.00 device HP 2.0MP High Definition
Webcam (0bda:57a4)
[ 8.852243] uvcvideo: No valid video chain found.
I think this last line is the reason the camera doesn't work.
http://git.linuxtv.org/media_build.git
and add some more debug info to the driver to determine what is
causing it to fail.
Regards,
Paulo
HP-EliteOne-800-G1
I have attached the 2 lsusb and dmesg log files. Is there anything I can do
to help? There isn't much information available to see how to debug this
further.
Thanks for looking!
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