On Tue, 19 Jun 2012, Philipp Dreimann wrote: > Hello, > > my usb webcam using the uvcvideo module is not working since kernel > 3.5-rc2. Kernel v3.4 is the last which is known to work, 3.5-rc3 is > broken too. > > The webcam does not work if it is connected to an usb2 port. If the > webcam is connected to an usb3 port it works. I compiled the uvcvideo > module from kernel 3.4 together with 3.5-rc3 to rule out the driver. > -- The behaviour did not change. (Thanks to Laurent Pinchart for the > idea.) > > Here is a log using usb3: > [ 1528.629506] usb 3-1: new high-speed USB device number 4 using xhci_hcd > [ 1529.364396] uvcvideo: Found UVC 1.00 device <unnamed> (046d:0821) > [ 1529.378344] input: UVC Camera (046d:0821) as > /devices/pci0000:00/0000:00:1c.6/0000:0e:00.0/usb3/3-1/3-1:1.2/input/input16 > -- Verifying whether the camera works -- successful. > [ 1571.789894] usb 3-1: USB disconnect, device number 4 > > > And the problematic one using usb2: > [ 1636.434459] usb 2-1.2: new high-speed USB device number 4 using ehci_hcd > [ 1637.237109] uvcvideo: Found UVC 1.00 device <unnamed> (046d:0821) > [ 1637.250484] input: UVC Camera (046d:0821) as > /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.2/input/input17 > -- Verifying whether the camera works -- not successful. > [ 1645.536061] uvcvideo: Failed to query (GET_DEF) UVC control 2 on > unit 2: -71 (exp. 2). > [ 1645.540292] uvcvideo: Failed to query (GET_DEF) UVC control 2 on > unit 2: -71 (exp. 2). > The last line is being repeated a lot, the Failed to query lines > appear every now and then.. -71 errors generally are caused by bad hardware. In this case, it may be a bad cable connection between the device and the EHCI controller. That would explain why the same device works okay when connected to xHCI. Have you checked the connections between the motherboard and the USB port, inside the computer case? Or have you tried using a different cable? How about attaching a different high-speed device to the same controller? > Another usb webcam is working fine, also using uvcvideo, and being > connected to an usb2 bus (as far as I see it). > > I attached two lsusb outputs, the webcam is once connected to the usb2 > and the other time to the usb3 port. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
