Hi Charlie,

On Wednesday 16 April 2008, Charlie Wyse wrote:
> Laurent Pinchart wrote:
> > On Tuesday 15 April 2008, Charlie Wyse wrote:
> >> Brandon Philips wrote:
> >>> On 12:33 Tue 15 Apr 2008, Charlie Wyse wrote:
> >>>> Whenever I run a make on the uvcvideo directory I get an error about
> >>>> the version.h file.  If I look at the file itself it is a 0 length
> >>>> file.  This file is removed with a make clean, so it looks like
> >>>> something in the make process isn't working.
> >>>
> >>> If you aren't using a SVN checkout or don't have svn installed the
> >>> version.h generation won't work.  The driver will still build however.
> >>>
> >>> Relevant source entries.
> >>>
> >>> Makefile:
> >>> <snip>
> >>>         @sh svn-version.sh > version.h 2>/dev/null
> >>>
> >>> uvc_driver.c:
> >>> <snip>
> >>> #ifndef DRIVER_VERSION
> >>> #define DRIVER_VERSION          "v0.1.0"
> >>> #endif
> >>>
> >>>> My QC 9000 works most of the time, but I figure this might be why all
> >>>> my devices come up as <unnamed>, even if I put the vender/product id
> >>>> into the uvc_driver.c file before running a make.  Any one know what
> >>>> is going on with that file?
> >>>
> >>> Your device comes up as <unnamed> because the device vendor didn't
> >>> include the optional string descriptor for it.  It shouldn't effect the
> >>> device functioning.
> >>>
> >>> What functional problems are you having with the device?
> >>>
> >>> Cheers,
> >>>
> >>>   Brandon
> >>
> >> Good to know about the version.h thing, I was afraid that was the
> >> problem as the 08ce was no in the uvc_driver.c file until I added it.
> >> We are having problems with some of our Logitech QC 5000's.  When we
> >> create the module on the same kernel we keep getting things in dmesg
> >> like the following:
> >> uvcvideo: Found UVC 1.00 device <unnamed> (046d:08ce)
> >> uvcvideo: Failed to query (1) UVC control 2 (unit 0) : -71 (exp. 26).
> >> uvcvideo: Failed to initialize the device (-5).
> >
> > -71 is -EPROTO. This is a low level error that can be caused either by
> > electrical issues (noisy environment, bad cables, bad USB ports, ...) or
> > a buggy device (firmware and/or hardware).
> >
> > The Logitech QC 5000 is known to be buggy. Sad but true. There are lots
> > of timing issues that are usually not triggered when using the webcam
> > under Windows. Linux has different timings, and things sometimes break
> > depending on your kernel version, on the USB controller, on the CPU
> > speed, ...
> >
> > Plugging the camera into another USB port might help. If it doesn't I'm
> > afraid there's not much I can do.
> >
> >> This prevents us from seeing any video and causes ekiga to crash with
> >> the following error in dmesg logs:
> >> Apr 15 10:51:39 duel kernel: uvcvideo: Failed to query (132) UVC control
> >> 4 (unit 2) : -32 (exp. 2).
> >
> > That's a non-fatal error that you will see quite often when you run into
> > timing issues. It basically means Ekiga tried to modify a control
> > (probably brightness in this case) and the device didn't answer the
> > request because of timings issues caused by a firmware bug.
> >
> >> On my other machine  I am getting past the dmesg part with both the QC
> >> 5000 and 9000, ekiga still doesn't want to switch video with whomever I
> >> call, but I believe that might be an ekiga problem.  I can still look at
> >> gstreamer-properties and see video without errors.  I was afraid this
> >> was just due to vendor ids not being listed, but it looks like I was
> >> troubleshooting down the wrong path.  Any ideas what could case those
> >> issues?
> >
> > Webcam bugs unfortunately :-( There might be a way to work around them in
> > software, but that would require in-depth analysis with a USB 2.0
> > analyser, comparing traces captured using Windows and Linux, ...
> >
> > Best regards,
> >
> > Laurent Pinchart
>
> Taht is unfortunate.  Laurent, do you have a recommended UVC camera?  We
> bought a bunch of 5000's and are pretty much getting what you said, most
> of them work, some just simply don't.  We are looking at the Quickcam
> 9000 and so far our tests are positive, do you think that might be a
> better option?

It should be. The current version of the QC Pro 9000 is based on a less-buggy 
chipset.

Best regards,

Laurent Pinchart
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