Похоже, что это произошло после обновления системы (дистр Slackware-current, обновился недели две назад). Вот вывод dmesg:
[ 3734.590023] usb 6-2: new full-speed USB device number 3 using uhci_hcd
[ 3734.834069] usb 6-2: New USB device found, idVendor=093a, idProduct=2628
[ 3734.834074] usb 6-2: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 3734.837099] gspca_main: pac7302-2.14.0 probing 093a:2628
[ 3734.842114] input: pac7302 as /devices/pci0000:00/0000:00:1d.0/usb6/6-2/input/input6
[12196.544006] usb 1-1: New USB device found, idVendor=093a, idProduct=2628
[12196.544128] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[12196.805878] Linux video capture interface: v2.00
[12196.813966] gspca: main v2.4.0 registered
[12196.816876] gspca: probing 093a:2628
[12196.856369] gspca: probe ok
[12196.858577] usbcore: registered new interface driver pac7311
[12196.859559] pac7311: registered