AppleALC causes system to freeze if connected to an external USB-C monitor

[najeebanwer]

I have macOS 12.0.1 (Monterey) installed on a Dell XPS 13 9300 (Ice Lake) notebook. However, this problem has existed with prior versions of macOS too. I am using OpenCore 0.7.4 (debug version) and the latest kexts.

The notebook is connected via a single USB-C cable to an external monitor (Dell U2719DC) for both power delivery to the notebook and for sending audio/video to the monitor.

Everything works correctly, except that if the external monitor is connected and I try to load AppleALC.kext the system freezes after boot (blank screen on both internal and external display; it looks like it happens when the system tries to display the login screen on the external display).

If I disconnect the external monitor macOS boots just fine and the audio devices are correctly recognized by AppleALC. I don't think it is a configuration issue and I have tried patching out IRQ conflicts using SSDTTime (SSDT-HPET) but that does not appear to help at all.

I have been using VoodooHDA and that worked fine, except that VoodooHDA will no longer load properly using the OpenCore bootloader from macOS 11.6 onward. Rather than try to figure out how to load VoodooHDA, I would like to figure out the problem with AppleALC since that is my preferred kext.

These are screenshots when AppleALC is loaded without the external display connected.

I have attached the boot logs and my config.plist. Please let me know what additional information I can provide. Note that this config.plist has AppleALC disabled so that I can boot with the external monitor connected.
opencore-Connected to USB-C Monitor.txt
opencore-Internal Display Only.txt
config.plist.zip
I would appreciate any help to resolve this issue.

[m0d16l14n1]

#1283

[m0d16l14n1]

Also this one is related to your problem too: #1616 (comment)

This actually happens on all Ice Lake laptops right now, if you connect external screen with speakers (TV, for example).

You can find the way to workaround that panic here at least that prevents panic, but you won't have any digital sound working.

I hope it's possible to fix that, but i did try all patching methods and etc

[najeebanwer]

@m0d16l14n1 thank you very much for the information. The solution provided by @kingo132 in #1283:

find：0E0000BE020000004889DF Replace：0E0000B848A30000EB0690
 in AppleALC/Resources/Controllers.plist is the solution.

I built AppleALC.kext with this modification and the audio works fine with the USB-C external monitor connected (both the internal speakers as well as the internal microphone).

Is it possible to make this the default patch in AppleALC/Resources/Controllers.plist for Ice Lake systems?

[m0d16l14n1]

@m0d16l14n1 thank you very much for the information. The solution provided by @kingo132 in #1283:

find：0E0000BE020000004889DF Replace：0E0000B848A30000EB0690 in AppleALC/Resources/Controllers.plist is the solution.

I built AppleALC.kext with this modification and the audio works fine with the USB-C external monitor connected (both the internal speakers as well as the internal microphone).

Is it possible to make this the default patch in AppleALC/Resources/Controllers.plist for Ice Lake systems?

Does the digital sound works? I mean speakers from connected TV or display?

[najeebanwer]

Does the digital sound works? I mean speakers from connected TV or display?

No, unfortunately there is no digital sound output to the connected monitor. I don't use that anyway.