lsusb:
Bus 001 Device 006: ID 13b1:000c Linksys WUSB54AG 802.11a/g Adapter [Intersil ISL3887]
The 13b1:000c Linksys WUSB54AG 802.11a/g Adapter [Intersil ISL3887] DOES NOT WORK with free software because the p54usb driver requires non-free firmware to support this device. After connecting this device, no new network interface appears. Kernel log excerpt from Trisquel GNU/Linux 8/Flidas is reproduced below:
localhost kernel: [ 80.624018] usb 1-7: new high-speed USB device number 6 using ehci-pci
localhost kernel: [ 80.760762] usb 1-7: New USB device found, idVendor=13b1, idProduct=000c
localhost kernel: [ 80.760767] usb 1-7: New USB device strings: Mfr=1, Product=2, SerialNumber=0
localhost kernel: [ 80.760771] usb 1-7: Product: Wireless A/G USB Network Adapter
localhost kernel: [ 80.760775] usb 1-7: Manufacturer: Cisco Linksys
localhost kernel: [ 81.048018] usb 1-7: reset high-speed USB device number 6 using ehci-pci
localhost kernel: [ 81.180565] usb 1-7: Loading firmware file /*(DEBLOBBED)*/
localhost kernel: [ 81.180570] 1-7: Missing Free firmware (non-Free firmware loading is disabled)
localhost kernel: [ 81.180625] usb 1-7: (p54usb) cannot load firmware /*(DEBLOBBED)*/ (-22)!
localhost kernel: [ 81.180686] p54usb: probe of 1-7:1.0 failed with error -22
localhost kernel: [ 81.180732] usbcore: registered new interface driver p54usb
localhost kernel: [ 81.181521] usb 1-7: Direct firmware load failed with error -2
This device DOES NOT work with free software. Weighing only a few grams, it is neither heavy enough to make a good paperweight.