Re: Logitech HD Webcam C525 does not work when connected to USB 2port, works on USB 3

From: Frederik Himpe
Date: Sun Jul 01 2012 - 08:34:57 EST


On Sat, 2012-06-30 at 22:12 -0400, Alan Stern wrote:
> On Sat, 30 Jun 2012, Frederik Himpe wrote:
>
> > Hello,
> >
> > I've got a Logitech HD Webcam C525 using the uvcvideo module and I use
> > Linux 3.5 RC4. When this camera is connected to a USB2 port, it does not
> > work most of the time. However it does work fine when connected to a USB
> > 3 port. In Windows it works on both ports.
>
> ...
>
> > Complete dmesg and lsusb -v output about a failed attempt (on USB 2
> > port) and a succeeded attempt (on USB 3) can be found on
> > http://artipc10.vub.ac.be/~frederik/webcam/
>
> A usbmon trace would be more helpful. Or perhaps a pair of traces, one
> for the USB-2 port and one for the USB-3 port. See the instructions in
> Documentation/usb/usbmon.txt.

OK, I created a usbmon trace both from the USB-2 port as the USB-3 port.
During the trace, I connected the USB webcam to the USB port and started
mplayer, which failed on USB-2 but worked fine on USB-3.

The two traces can be found here:
http://artipc10.vub.ac.be/~frederik/webcam/

Thanks!
--
Frederik Himpe <fhimpe@xxxxxxxxxx>

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