[bug] powertop, suggestion about usbsuspend

[Alexe Fisher]

Hi Arjan!
powertop check if usbcore autosuspen is enabled by checking /sys/bus/usb
interface. but will make wrong suggestion if one of devices is
blacklisted or set to NULL ( but NULL if i'm correct mean: suspend now,
 and only negative option like -1 will disable autosuspend )


for example this i get on my system:
cat /sys/bus/usb/devices/*/power/autosuspend
0   <== usb mous
2
2
2
2
2

in this case powertop will suggest to enable autosuspend
i think better way to check if it enabled is to do:
cat /sys/module/usbcore/parameters/autosuspend

Regards
Alex