[BUG] Black screen 3 minutes after booting, CoffeeLake UHD 630

[Amandeep]

Told ya

It didn't solve the original problem though. So, it doesn't give problems but neither does it help me with anything. Just filling up my precious little EFI partition

 

[RehabMan]

UPDATE: I have more information. After this I change a value on config.plist with Clover Configurator and I have again 3 min of black screen. But I try another thing: Put again Lilu and Whatevergreen on L/E and EFI/KEXTS/OTHER. Restart. And remove again the kexts from L/E and EFI/CLover... Restart.... and no black screen.

I restart and turn off my laptop three times and it works.

I can't understand why, but it works.

What do you mean by "change a value on config.plist"?

I wrote at the start that it is a case of more often than not. Also, using backlight injector will give black screen definitely.

Keep in mind AppleBacklightInjector requires correct SSDT-PNLF.aml.

 

[Amandeep]

What do you mean by "change a value on config.plist"

Sometimes just changing the value of something in config.plist resulted in no backlight issue. Changes were enabling/disabling renames in the ACPI.

Keep in mind AppleBacklightInjector requires correct SSDT-PNLF.aml.

If backlight is working fantastic everywhere(backlight control bar n all) except at the boot, isn't it correct one?

 

[RehabMan]

Sometimes just changing the value of something in config.plist resulted in no backlight issue. Changes were enabling/disabling renames in the ACPI.

Well, those are substantial ACPI changes...

If backlight is working fantastic everywhere(backlight control bar n all) except at the boot, isn't it correct one?

No ideas without full PR files as per FAQ.

 

[Amandeep]

Well, those are substantial ACPI changes...

I dont understand why would changing something like removing kexts or enabling/disbaling something like acpi renames would bypass black screen. Maybe doing those big changes resets something that is causing these black screens..

No ideas without full PR files as per FAQ.

Here.

 

[RehabMan]

I dont understand why would changing something like removing kexts or enabling/disbaling something like acpi renames would bypass black screen. Maybe doing those big changes resets something that is causing these black screens..

ACPI names determine which kexts load (for example, without GFX0->IGPU rename, no IGPU PM kexts loaded).

If backlight is working fantastic everywhere(backlight control bar n all) except at the boot, isn't it correct one?

Here.

What do you mean by "except at boot"?

 

[Amandeep]

ACPI names determine which kexts load (for example, without GFX0->IGPU rename, no IGPU PM kexts loaded).




What do you mean by "except at boot"?

The problem is that these work in reverse too. If I disabled something right now then a very high chance laptop will boot without issue. Now after some reboots the problem comes again. Now when you go and enable that thing and boot the macjhine will highly likely boot without issue. both enabling/disabling something can make it work.

What do you mean by "except at boot"?

We have the issue of no backlight during boot na.

 

[RehabMan]

The problem is that these work in reverse too. If I disabled something right now then a very high chance laptop will boot without issue. Now after some reboots the problem comes again. Now when you go and enable that thing and boot the macjhine will highly likely boot without issue. both enabling/disabling something can make it work.

Some kind of kernel cache/timing related problem.

We have the issue of no backlight during boot na.

You're referring to the 3 minute black screen issue, right?

Someone needs to investigate what IGPU registers change at that transition. Requires someone knowledgeable enough (and who has the hardware in front of them) to modify a kext like IntelBacklight.kext or AppleIntelInfo.kext to dump key IGPU registers on a timer, in order to see what is changing. Then whatever needs initialization can be done in SSDT-PNLF.aml.

 

[Amandeep]

You're referring to the 3 minute black screen issue, right?

Yes.

 

[RehabMan]

Yes.

And you have confirmed it is a backlight issue?
That is... you can see an image if you shine a bright light onto the screen during that 3 min window?