Backlight control with AMD gpu; works with intel obviously (weird on amd)

[Ericarthurc]

System:
Dell Precision 7510
i7 6820HQ
HD 530, AMD w5170m firepro
8gb DDR4 Ram
Sata drive
Clover 4444

So Rehabman helped me a week ago to disable my dedicated amd card so the system could run just on the intel graphics with a ssdt-discreatespoof.aml and that works great! But I did some more digging with my amd card (cape verde 7000 series). And remembered the amdradeonx4000 kext fix. So I edited that kext (I attached the edited one). It's an edit on the 'cail properties' key. And then added whatevergreen.kext and disabled igpu in my bios. The system boots into the OS just fine and system report actually shows the graphics card as an AMD R9 m375, which is what it actually is! (well its a m375x clocked a little higher), but close enough. And it has full system acceleration! Even played a game on it and it ran just fine (comparable performance to windows in the game). Sleep and wake actually work too! The only issue is the backlight control, which I know is tied to the intel igpu. I attached a link to a video I made of what the brightness slider bar does with the igpu disabled and just the amd graphics (the system works with both enabled, but obviously can't use the amd card). As I slide the bightness from 0-50% is more like 0-100% then it repeats like 50-60% is like 0%-100% and so one, up and down in brightness. It's not a big deal just wondering if this is fixable? I know using the igpu is recommended, but I like having the power of the amd card. Thanks in advance!

Brightness slider video:
https://drive.google.com/file/d/1Qk93qwzKooR4JsBIPHTrpnm2-9iPaGM-/view?usp=sharing

Attached my problem reporting files:

 

[RehabMan]

System:
Dell Precision 7510
i7 6820HQ
HD 530, AMD w5170m firepro
8gb DDR4 Ram
Sata drive
Clover 4444

So Rehabman helped me a week ago to disable my dedicated amd card so the system could run just on the intel graphics with a ssdt-discreatespoof.aml and that works great! But I did some more digging with my amd card (cape verde 7000 series). And remembered the amdradeonx4000 kext fix. So I edited that kext (I attached the edited one). It's an edit on the 'cail properties' key. And then added whatevergreen.kext and disabled igpu in my bios. The system boots into the OS just fine and system report actually shows the graphics card as an AMD R9 m375, which is what it actually is! (well its a m375x clocked a little higher), but close enough. And it has full system acceleration! Even played a game on it and it ran just fine (comparable performance to windows in the game). Sleep and wake actually work too! The only issue is the backlight control, which I know is tied to the intel igpu. I attached a link to a video I made of what the brightness slider bar does with the igpu disabled and just the amd graphics (the system works with both enabled, but obviously can't use the amd card). As I slide the bightness from 0-50% is more like 0-100% then it repeats like 50-60% is like 0%-100% and so one, up and down in brightness. It's not a big deal just wondering if this is fixable? I know using the igpu is recommended, but I like having the power of the amd card. Thanks in advance!

Brightness slider video:
https://drive.google.com/file/d/1Qk93qwzKooR4JsBIPHTrpnm2-9iPaGM-/view?usp=sharing

Attached my problem reporting files:

"Problem Reporting" files are incomplete.
Read FAQ, "Problem Reporting" again. Carefully. Attach all requested files/output.
https://www.tonymacx86.com/threads/faq-read-first-laptop-frequent-questions.164990/
Use the gen_debug.sh tool mentioned in the FAQ, that way it is less likely you'll omit something.

 

[Ericarthurc]

"Problem Reporting" files are incomplete.
Read FAQ, "Problem Reporting" again. Carefully. Attach all requested files/output.
https://www.tonymacx86.com/threads/faq-read-first-laptop-frequent-questions.164990/
Use the gen_debug.sh tool mentioned in the FAQ, that way it is less likely you'll omit something.

Here is the problem files

 

[RehabMan]

Here is the problem files

AppleBacklightInjector.kext technique is only for Intel graphics.
You'll need to at least remove that much.
And to get it working, you'll probably need to do some reversing of AMD backlight control kexts... an ioreg from a Mac with AMD + built-in screen (maybe an iMac17,1) may be useful as it will show you which objects are loading from which kexts.

 

[Ericarthurc]

AppleBacklightInjector.kext technique is only for Intel graphics.
You'll need to at least remove that much.
And to get it working, you'll probably need to do some reversing of AMD backlight control kexts... an ioreg from a Mac with AMD + built-in screen (maybe an iMac17,1) may be useful as it will show you which objects are loading from which kexts.

Okay, thanks! I actually have access to a real Mac with a Radeon 450 in it! I will grab an IOReg from it.

 

[Ericarthurc]

AppleBacklightInjector.kext technique is only for Intel graphics.
You'll need to at least remove that much.
And to get it working, you'll probably need to do some reversing of AMD backlight control kexts... an ioreg from a Mac with AMD + built-in screen (maybe an iMac17,1) may be useful as it will show you which objects are loading from which kexts.

This is from a real iMac 18,2 with an AMD Radeon 560. The GFX0 shows has AppleBacklightDisplay under it.

 

[RehabMan]

This is from a real iMac 18,2 with an AMD Radeon 560. The GFX0 shows has AppleBacklightDisplay under it.

Look at PNLF.
Note _UID="10", and refnum=0, type=0x49324300 (likely injected with ACPI/_DSM).
Seems to cause AppleMCCSControlCello to load...

 

[Ericarthurc]

Look at PNLF.
Note _UID="10", and refnum=0, type=0x49324300 (likely injected with ACPI/_DSM).
Seems to cause AppleMCCSControlCello to load...

Just removed the AppleBacklightInector.kext and the brightness slider is working just fine now.. haha. thanks Rehabman.

Hopefully that IOReg from the real 18,2 can help you out in the future!

I am asking just for knowledge sake, but where do you see where it loads the AppleMCCSControlCello in the 18,2 IOReg? I see the PNLF with _UID = 10 and refnum = 0x0.

 

[RehabMan]

Just removed the AppleBacklightInector.kext and the brightness slider is working just fine now.. haha. thanks Rehabman.

Hopefully that IOReg from the real 18,2 can help you out in the future!

I am asking just for knowledge sake, but where do you see where it loads the AppleMCCSControlCello in the 18,2 IOReg? I see the PNLF with _UID = 10 and refnum = 0x0.

That ioreg will probably help you customize your brightness levels (might need that for correct levels).
Just look at the tree under PNLF@0, and you see the class names that load under it.

 

[Ericarthurc]

That ioreg will probably help you customize your brightness levels (might need that for correct levels).
Just look at the tree under PNLF@0, and you see the class names that load under it.

Oh I see it now, I was searching for PNLF in the top bar so it was isolating that value and not showing whats under it. Probably can mark this one as solved, thanks!

Do you have a guide for the custom levels?