This patch looks great, but isn't quite sufficient. This will set the
autosuspend timeout for all existing USB devices to 0 when activated,
but will not modify the timeout for new USB devices. This can be set by
writing to /sys/module/usbcore/parameters/autosuspend. Both this and the
existing behavior of the script are required to make sure that all USB
devices connected to the system when on battery have autosuspend=0.
I'm not sure how to set the default power level for new devices - it
would probably require some HAL hooks.
Attached is a modified version of the script with this change.
- Michael
#! /bin/sh
#
# Laptop mode tools module: USB Auto Suspend power saving mode.
#
if [ x$CONTROL_USB_AUTOSUSPEND = x1 ] ; then
if [ $ON_AC -eq 1 ]; then
if [ -f /sys/module/usbcore/parameters/autosuspend ]; then
echo 2 > /sys/module/usbcore/parameters/autosuspend
$LM_VERBOSE && echo "Disabling auto suspend mode for new USB
devices."
fi
if [ -d /sys/bus/usb/devices ]; then
for usb_device in /sys/bus/usb/devices/*;
do
usb_device=`basename $usb_device`;
if [ -f /sys/bus/usb/devices/$usb_device/power/autosuspend ];
then
echo 2 > /sys/bus/usb/devices/$usb_device/power/autosuspend;
$LM_VERBOSE && echo "Disabling auto suspend mode for usb
device $usb_device." >> $OUTPUT
fi
if [ -f /sys/bus/usb/devices/$usb_device/power/level ]; then
echo "auto" > /sys/bus/usb/devices/$usb_device/power/level;
$LM_VERBOSE && echo "Setting auto power level for usb
device $usb_device." >> $OUTPUT
fi
done
else
#This will rarely happen.
$LM_VERBOSE && echo "There are no USB devices." >> $OUTPUT
fi
else
if [ -f /sys/module/usbcore/parameters/autosuspend ]; then
echo 0 > /sys/module/usbcore/parameters/autosuspend
$LM_VERBOSE && echo "Enabling auto suspend mode for new USB
devices."
fi
if [ -d /sys/bus/usb/devices ]; then
for usb_device in /sys/bus/usb/devices/*;
do
usb_device=`basename $usb_device`;
if [ -f /sys/bus/usb/devices/$usb_device/power/autosuspend ];
then
echo 0 > /sys/bus/usb/devices/$usb_device/power/autosuspend;
$LM_VERBOSE && echo "Enabling auto suspend mode for usb
device $usb_device." >> $OUTPUT
fi
if [ -f /sys/bus/usb/devices/$usb_device/power/level ]; then
echo "auto" > /sys/bus/usb/devices/$usb_device/power/level;
$LM_VERBOSE && echo "Enabling auto power level for usb
device $usb_device." >> $OUTPUT
fi
done
else
#This will rarely happen.
$LM_VERBOSE && echo "There are no USB devices." >> $OUTPUT
fi
fi
else
$LM_VERBOSE && echo "USB auto suspend is disabled." >> $OUTPUT
fi
