[Guide] Patching DSDT/SSDT for LAPTOP backlight control

[RehabMan]

On 8570p and Radeon, only DSDT patches are required to get fully working backlight with vanilla AppleBacklight.kext. It works as it works on real macs, with smooth transitions and detects correctly wether AC is plugged or not.

NVRAM works and thats not the problem. If I'm on battery so that the backlight is about 80% and go to sleep or restart, backlight is still 80%. Also when I plug or unplug AC the backlight will adjust accordingly.

The problem is that if you shutdown with AC plugged so that your backlight is 100% then you unplug AC (while laptop is still turned off) and then turn on the laptop, OS X doesn't get the information that the AC was unplugged while laptop was turned off. On Windows this works and I would guess that it would work on real macs also but i'm not sure.

You probably neglected to provide correct data for AppleBacklight.kext and are ending up with 'Default'.

You should look at the Info.plist.

Note: This guide is focused on Intel backlight control.

 

[Amble]

You probably neglected to provide correct data for AppleBacklight.kext and are ending up with 'Default'.

You should look at the Info.plist.

Note: This guide is focused on Intel backlight control.

Sorry what data are you talking about?

 

[RehabMan]

Sorry what data are you talking about?

You should study the Info.plist in AppleBacklight.kext.

It is brightness data corresponding to display devices. It would be helpful if you had an ioreg from a Mac which has Radeon with backlight control (all-in-one Mac with Radeon?).

 

[Amble]

You should study the Info.plist in AppleBacklight.kext.

Oh yes the "ApplePanels", sorry I misread what you said. But could that really be because of that?

Just to make sure you understood me correctly, as it is sometimes hard to explain some things because my native language is not english.

1. AC plugged, brightness 100%, shutdown, restart and brightness is correctly 100%
2. AC unplugged, brightness 80%, shutdown, restart and brightness is correctly 80%
3. AC plugged, brightness 100%, shutdown, unplug AC, restart and brightness is incorrectly 100%

So on your Intel IGPU, number 3 works so that the brightness is 80% when OS X boots? I thought it might be something like OS X doesn't get the information on boot that there has been a change in the AC/battery status while laptop was shutdown (ACPIBatteryManager).

On my laptop this works with Windows 8.1 and earlier but is also broken with Windows 10.

 

[RehabMan]

Oh yes the "ApplePanels", sorry I misread what you said. But could that really be because of that?

No idea. I have no hardware like yours.

You should do some research and try to patch it (or build an injector). There are topics which cover it for Intel that you should research, even though the details are likely to be different for your hardware.

Just to make sure you understood me correctly, as it is sometimes hard to explain some things because my native language is not english.

1. AC plugged, brightness 100%, shutdown, restart and brightness is correctly 100%
2. AC unplugged, brightness 80%, shutdown, restart and brightness is correctly 80%
3. AC plugged, brightness 100%, shutdown, unplug AC, restart and brightness is incorrectly 100%

System will always restore brightness to the previous setting on restart. It does not save separate brightness levels for AC vs. battery. Changing brightness level due to AC/battery happens only on transitions.

Seems like you're nitpicking...

 

[Amble]

No idea. I have no hardware like yours.

You should do some research and try to patch it (or build an injector). There are topics which cover it for Intel that you should research, even though the details are likely to be different for your hardware.



System will always restore brightness to the previous setting on restart. It does not save separate brightness levels for AC vs. battery. Changing brightness level due to AC/battery happens only on transitions.

Seems like you're nitpicking...

No it works with Windows. On boot Windows checks wether there is AC or battery in use and then boots with the proper brightness level. Have you tested scenario number 3 on real macs to see how it should work?

 

[nubuntu]

Hi RehabMan , I just want to share my working patch for LG Gram 15Z950 ,
may be you want to add it to your repo, thanks...

 

[RehabMan]

Hi RehabMan , I just want to share my working patch for LG Gram 15Z950 ,
may be you want to add it to your repo, thanks...

Such patches belong in a laptop specific guide. Other than battery patches (which are extensive), I'm not adding other machine specific patches to my patch repo.

Laptop guides should be posted here: http://www.tonymacx86.com/el-capitan-laptop-guides/

 

[Wong98]

SSDT.aml (from ssdtPRgen.sh)

What is this ?

 

[RehabMan]

What is this ?

http://www.tonymacx86.com/el-capita...01-guide-native-power-management-laptops.html