It's nice when things work the way they are supposed to. For instance, it's nice to see dmesg output that tells you that you're connected USB device is not connected at full speed. In the below dmesg output, I see that notification when I connect my 5D Mark II, a high-speed USB device, to a low speed USB port:
[14381.652509] usb 4-2.3: new full-speed USB device number 4 using uhci_hcd
[14381.755506] usb 4-2.3: not running at top speed; connect to a high speed hub
[14381.778506] usb 4-2.3: New USB device found, idVendor=04a9, idProduct=3199
[14381.778510] usb 4-2.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[14381.778513] usb 4-2.3: Product: Canon Digital Camera
[14381.778516] usb 4-2.3: Manufacturer: Canon Inc.
So, I disconnect the camera:
[14436.920306] usb 4-2.3: USB disconnect, device number 4
And then reconnect it to a USB port that I know is high speed:
[14487.803026] usb 1-6: new high-speed USB device number 7 using ehci_hcd
[14487.922212] usb 1-6: New USB device found, idVendor=04a9, idProduct=3199
[14487.922217] usb 1-6: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[14487.922220] usb 1-6: Product: Canon Digital Camera
[14487.922223] usb 1-6: Manufacturer: Canon Inc
The second dmesg output does not indicate that it has negotiated at full speed, but then again, it does not give me the "not running" error. So in this case, we assume that the device is connected at the highest speed.
Cool. I can now move on to the more important stuff..downloading my media in Shotwell at the highest speed possible!