Comment 272 for bug 312756

Revision history for this message
bdkoepke (bdkoepke) wrote : Re: support graphics card hot switch

One more update,

I ran kernel 2.6.28 with dsdt from initramfs support (too lazy to compile my own kernel...)

I modified the _SP3 method I attached above, and removed the first condition (line 15029), and its corresponding closing bracket.

If (LEqual (P3MO, 0x01)) {
}

After removing the lines, I ran

echo '\_SB.PCI0.RP00.VGA._PS3' > /proc/acpi/call

and miraculously my power consumption went down from 20W to 12W.

(Horay! I can actually get eight hours of battery life now!)

I've got a few questions for anyone with even a remote knowledge of ACPI.

First of all, I have thus-far assumed that LEqual stands for "Less than or equal to". Under this assumption, I don't understand how P3MO would ever be greater than 0x01 because it isn't changed to anything but zero or one.

This is every line I found P3MO on...

14781: Name (P3MO, 0x00)
14885: Store (One, \_SB.PCI0.RP00.VGA.P3MO)
14889: Store (Zero, \_SB.PCI0.RP00.VGA.P3MO)
15157: Store (0x00, P3MO)

Maybe someone could enlighten me, or should I post this somewhere else?

Any help would be greatly appreciated.