https://bugzilla.kernel.org/show_bug.cgi?id=36322
--- Comment #13 from Lee, Chun-Yi <j...@novell.com> 2011-06-03 08:16:10 ---
It's a great hack.
Could you please also try acpi_osi="!Windows 2009"? maybe it also work like
acpi_osi="Linux"?
--- Comment #14 from Lee, Chun-Yi <j...@novell.com> 2011-06-03 08:51:25 ---
(In reply to comment #12)
> I did some reverse engineering and trying. Here are my results and some
> thoughts:
>
Thank's for your great hacker.
> Calling _SB.PCI0.LPCB.EC0.BRXP "activates" the brightness which is set
> in the BLVL.
>
> The DSDT contains this code three times:
>
> If (LAnd (LLess (OSYS, 0x07D6), LEqual (SGST, Zero)))
> {
> BRXP ()
> } Else {
> ...
> }
>
> OSYS on my machine is 0x07D9 ("Windows 2009"), while there is 0x03E8 ("Linux")
> available in the os setup (_INI).
> SGST, whatever that may be, is currently 0.
>
Could you please also try acpi_osi"!Windows 2009" ?
> Method (BRXP, 0, NotSerialized)
> {
> Multiply (DerefOf (Index (PNLT, BLVL)), 0x64, Local1)
> Divide (Local1, 0x0100, , Local2)
> ^^^GFX0.AINT (One, Local2)
> }
>
> So let's look for AINT. Only BRXP calls this method.
>
> AINT, stripped down, is:
> PARD()
> Store (Divide (Multiply (Arg1, 0xFF), 0x64, ), BCLP)
> Or (BCLP, 0x80000000, BCLP)
> Store (0x02, ASLC)
> Store (One, ASLE)
>
The AINT is the mathod the control the backlight base on Intel OpRegion spec.
>
> I still don't know the correct way to set the brightness.
> * Use the "Linux" OSYS?
It can fix the brightness control problem on your machine, but conflict with
current kernel acpi strategy: bit newest windows version (Windows 7)
> * Call BRXP after each change to the brightness?
> * Call ISBC? This would be cool because you don't have 10 but 256 different
> states.
I thought it's too specifically and I cann't direct evaluate a special acpi
method in acer-wmi.
On the other hand,
Per Windows 7 path, DSDT follow standard acpi way, brightness control must
handle by acpi/video.c but not in acer-wmi :
_Q8E/_Q8F -> Nodify GFX0.DD02 -> acpi/video.c -> evaluation _BCM ->
LPCB.EC0.BLVL
>
> I hope that this helps you with updating the driver.
I still want to know what _REAL_ way acer doing in Windows7, then we need find
a way to do the same thing with Windows7.
I don't thing they direct access BRXP in their driver, it's very dirty.
--
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.
------------------------------------------------------------------------------
Simplify data backup and recovery for your virtual environment with vRanger.
Installation's a snap, and flexible recovery options mean your data is safe,
secure and there when you need it. Discover what all the cheering's about.
Get your free trial download today.
http://p.sf.net/sfu/quest-dev2dev2
_______________________________________________
acpi-bugzilla mailing list
acpi-bugzilla@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
