USB Device Voltage cut off

kawamura · 08-03-2010, 10:24 AM

Hello,

I'm using RHEL5 and checking USB devices. Now what I'm trying is to cut off (turn off) the voltage supplied to USB device.

Quote:

# uname -r
2.6.29.6.99.custom.22122009
# cd /sys/bus/usb/devices/2-1/power
# ls
active_duration autosuspend connected_duration level wakeup
# echo "suspend" > level

But, it's not possible to turn off the power of USB devices, although e.g. only iPod was released from the USB device by this commands.

Is there a ways to directly turn off the voltage of USB dev on linux?

thanks in advance.
Gen

jefro · 08-04-2010, 03:16 PM

roseroyal · 08-05-2010, 05:24 AM

you have to Mount the Pen Drive.Then You have to Apply ACPI Command For it.But You have to Mount it First then You can apply this Command.