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i3/i5/i7 Switcheroo function

Posted: 10 Feb 2011, 05:29
by brokenman
My new laptop is a HP dv6 and has the dual graphics switcheroo function that allows swapping between hi and low power usage for graphics. The problem is that under linux, both of the cards and switched on and it is always using the hi power option. My bios has no option to turn this switching function off so i hunted down an alternative.

Here is a kernel module that you can use to make acpi calls through /proc/acpi and switch off the hi power version.

have a look and see what the 'rate of power usage' is for your machine:
grep rate /proc/battery/BAT0/state

Unpack the source
Enter into the directory and type: make
Once compiling has finished run the test script

Code: Select all

Trying \_SB.PCI0.P0P1.VGA._OFF: failed
Trying \_SB.PCI0.P0P2.VGA._OFF: failed
Trying \_SB_.PCI0.OVGA.ATPX: failed
Trying \_SB_.PCI0.OVGA.XTPX: failed
Trying \_SB.PCI0.P0P3.PEGP._OFF: works!
if you see works! like above then the kernel module has found a way to disable the hi power function. Now just echo this to the acpi file.
echo '\_SB.PCI0.P0P3.PEGP._OFF' > /proc/acpi/call

Hopefully now you can see a difference in the power rate:
cat /proc/acpi/battery/BAT0/state