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

From: Alan Stern
Date: Sat Jun 30 2012 - 22:12:52 EST


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.

Those disconnections in your dmesg logs are not normal. They could be
caused by a hardware incompatibility or by a software problem --
although if it were software then I would expect the same thing to
happen with the USB-3 port.

Alan Stern

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