On Mon, Feb 22, 2010 at 09:51:19AM +0800, Zhang Rui wrote:
> On Fri, 2010-02-19 at 21:54 +0800, Matthew Garrett wrote:
> > My system statically initialises the variable containing the current
> > brightness to 100, but doesn't include 100 in the list of valid
> > brightnesses.
>
> sorry, I don't understand.
> does the video driver set the backlight to 100, which is not a valid
> value in the _BCL package?
No, the firmware does.
> > Right now this causes us to stop believing _BQC. However,
> > the enxt thing we do is set the brightness to maximum anyway - at this
> > point _BQC will now return a correct value.
>
> hmmm, could you attach the acpidump please?
The relevant bits are:
Name (BRIG, 0x64)
Method (_BQC, 0, Serialized)
{
Store (BRIG, Local0)
Return (Local0)
}
Method (_BCM, 1, Serialized)
{
...
Store (Arg0, BRIG)
0x64 is an invalid value as far as _BCL goes. So, _BQC will give an
invalid response until we set a value - after that, it'll be correct.
--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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