How can I find out what the settings in /sys/bus/usb/devices//power mean?

I am trying to hammer out an issue with one of my USB hard drives constantly falling asleep and waking back up. I made my way into /sys/bus/usb/devices/3-4/power .. inside are a number of settings:

me@mybox:/sys/bus/usb/devices/3-4/power$ dir
active_duration control runtime_status
autosuspend level runtime_suspended_time
autosuspend_delay_ms persist
connected_duration runtime_active_time

Each is a file with a setting in it.. but there is no description of what the settings mean. For example, if I open autosuspend in nano, the only thing inside it is 2 .. nothing else. How can I find out what 2 means, and what the other possible values are?

Thanks

1 Answer

Please check here: I suggest you do:

sudo -i
echo -1 > /sys/bus/usb/devices/3-4/power/autosuspend_delay_ms
exit

If that fixes it for you, then make it persistent:

gksudo gedit /etc/rc.local

Right above the line exit 0, add:

echo -1 > /sys/bus/usb/devices/3-4/power/autosuspend_delay_ms

Proofread, save and close gedit.