Sony SZ Brightness DSDT

[g33j]

Hey all, I'm kind of new at this so please be patient (I'm running 10.6.6 on a VAIO SZ, GMA950 27a2)

 

I got some degree of backlight control on my laptop using the 10.6.2 kexts from this website, combined with

 

       Device (PNLF)
       {
           Name (_HID, EisaId ("APP0002"))
           Name (_CID, "backlight")
           Name (_UID, 0x0A)
           Name (_STA, 0x0B)
       }

 

This gives me a slider and fn+scroll lock and fn+insert allow me to change brightness as well. (In windows, the keys are f5, f6).

 

 

This would be fine, except after the 0x3f brightness step, the brightness goes down and up again. Also, 0x00 turns the screen off completely, and I have to reboot!

 

So, I've been trying to limit brightness between 0x01 and 0x3f, but have been unsuccessful!

 

In ioreg (AppleBacklightDisplay), the brightness min is listed as 0x00, max as 0x80.

 

I can't figure out where these numbers come from

 

My understanding is that the _BCL method should determine these values, but I can have it return anything and the min and max remain the same.

 

Then, I tried to edit IOGraphicsFamily.kext with:

<key>AppleBacklightDisplay</key>
<dict>
<key>IODisplayParameters</key>
<dict>
<key>brightness</key>
<dict>
<key>min</key>
<integer>1</integer>
</dict>
</dict>
</dict>

 

That didn't change it either, though I must confess to not really knowing what I'm doing. AppleBacklightDisplay's CFBundleIdentifier is com.apple.io.kit.IOGraphicsFamily, so it doesn't seem to be using AppleBacklight.kext.

 

Does anyone have any idea where these min/max brightness levels are coming from? Thanks!

[g33j]

I just deleted _BCM, _BCL, _BQC as well as the vaio specific SBRT and GBRT (get and set brightness), and everything works as before.

 

It seems that it's only using the PNLF device. Where are my min and max brightness values coming from, in that case?