Gentoo/USB Power Saving

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USB Power Saving

Linux has the ability to poweroff USB devices and let the USB device request to wake up.

Warning: Many optical mice does not support this, as once their power is down they cannot detect motion

Configuration

Linux Kernel Configuration:
  Device Drivers  --->
    [*] USB support  --->
      <M>   Support for Host-side USB
      [*]     USB runtime power management (autosuspend) and wakeup

Set auto suspend to 1 seconds:

File: /etc/modprobe.d/usb.conf
options usbcore autosuspend=1

Enforce for every device:

File: /etc/udev/rules.d/60-power.rules
SUBSYSTEM!="usb", GOTO="power_usb_rules_end"
ACTION!="add", GOTO="power_usb_rules_end"

KERNEL=="[0-9]*:*", WAIT_FOR_SYSFS="bInterfaceProtocol"
PROGRAM="/bin/sleep 0.1"

ATTR{power/level}=="*", ATTR{power/level}="auto"

LABEL="power_usb_rules_end"