External display audio output may not work after reinserting the cable

[Anonyame]

macOS Version

Big Sur

What is your CPU's model?

AMD Ryzen 7 5800H with Radeon Graphics

Please describe the behaviour in detail.

In my workflow, I use a VX2731-2K-HD monitor (with 2 HDMI + 1 DP + 1 x 3.5mm audio output) connected to a Beelink SER5 Max running Hackintosh with the latest version of NRed and another desktop PC with Windows installed. The Beelink SER5 Max is connected to VX2731-2K-HD via HDMI, while the desktop PC connects through DP.

Upon startup, I switch VX2731-2K-HD's input source to HDMI for audio output which works fine; then when switching to the desktop with Windows installed and using it as an input source, its audio can properly pass through VX2731-2K-HD. However, after returning the monitor's input source to Beelink SER5 Max, no sound is emitted from 3.5mm Audio Output on VX2731-2K-HD anymore.

If I switch back to using the desktop PC as an input source again at this point, then indeed audio can still be outputted through the 3.5mm Audio Output of VX2731-2K-HD.

What should've happened instead?

VX2731-2K-HD should be able to continue outputting the sound from the Beelink SER5 Max Hackintosh via its 3.5mm audio output.

If applicable, attach the .gpuRestart, .panic, etc file related to this issue.

No crash log created during this action.

[github-actions]

Greetings. It seems like this is the first issue you open on this repository.

We are letting you know that these are for bug reports or feature requests. Most of the reports we receive in this GitHub Organisation are user errors.

For the sake of saving time, here are the most common cases:

• Outdated version of this kext.
• Conflicts with other kexts (e.g. WhateverGreen).
• Issues caused by other kexts like memory corruption (e.g. AirportItlwm).
• Intended behaviour by Apple (e.g. V-Sync or cursor rendering).
• Using cheap hacks like kext/library downgrades (e.g. OCLP, BFixup).
• Duplicate kexts.
• Malformed config.plist caused by configurator software (OCAT, OCC, etc).
• Lack of TSC synchronisation or use of badly programmed TSC kext (only use ForgedInvariant).
• Outdated macOS minor version (e.g. macOS 11.0.0 instead of latest).
• Using beta versions of macOS.
• Using the kext during installation or update. There is a Lilu bug which makes macOS stall during the last install phase.
• Incorrect SMBIOS. Please use iMac20,1, MacBookPro16,3, MacPro7,1 or iMacPro1,1.
• (e)DP link training failure. -NRedDPDelay will fix this as mentioned in the README. This is last resort, black screen can be caused by other factors mentioned.
• Insufficient VRAM size.

We will never support the use of configurator software, solutions like OCLP/BFixup, or using macOS beta versions.

This issue will be looked over by the respective maintainer when they can. In the meantime, look if you can resolve this yourself via checking the above.

Be patient, we are hobbyists.

[Anonyame]

I am preparing to test if, when I set the input source of VX2731-2K-HD to DP during the Beelink SER5 Max startup and then switch it back to HDMI after booting up, the output will be normal or not.

[Anonyame]

I am preparing to test if, when I set the input source of VX2731-2K-HD to DP during the Beelink SER5 Max startup and then switch it back to HDMI after booting up, the output will be normal or not.

Tested. Can't work.

[Anonyame]

Test for more times, and find that this phenomenon sometimes occurs and sometimes it doesn't. Currently I'm preparing for more observations to determine whether this issue is just a rare occurrence or not.

Thx!

[VisualEhrmanntraut]

I was able to replicate something similar by accident actually. After reconnecting the cable the sound device didn't show up, and then I reconnected the cable again and it showed up.

[Anonyame]

I was able to replicate something similar by accident actually. After reconnecting the cable the sound device didn't show up, and then I reconnected the cable again and it showed up.

Thx for your test! The phenomenon here is pretty much the same as what you have there, however, when I first encountered this issue, no matter how many times I switched or unplugged and reconnected the HDMI cable, the sound device did not show up in the system info list. But during my latest test, despite multiple attempts at switching devices around, the sound device connected properly each time. Really very weird.

[Anonyame]

Test for more times and a temporary solution that doesn't require modifying the source code. Just follow these steps:

1. Lock the screen and wait for a while until macOS shut the screen down;
2. Wait for a while, left the screen off;
3. Wake macOS up, the screen will open, unlock the system.
4. And we will find that the sound device has been back.

Idk whether I need to close the issue or not, should I close it?

Thx!

[Anonyame]

Test for more times and a temporary solution that doesn't require modifying the source code. Just follow these steps:

1. Lock the screen and wait for a while until macOS shut the screen down;
2. Wait for a while, left the screen off;
3. Wake macOS up, the screen will open, unlock the system.
4. And we will find that the sound device has been back.

Idk whether I need to close the issue or not, should I close it?

Thx!

Oh, there's still something I need to add. Sometimes, after using this recipe, unplugging and then reconnecting will no longer cause sound devices to be lost.

[VisualEhrmanntraut]

Merging with #225 as it's probably the same underlying cause.