MHWD Automatically disables HDMI Audio on Nvidia PRIME Proprietary Driver

Hi, as I'm new to linux and github I am not sure if this issue has been reported or issued before.

I am using Manjaro on a laptop with hybrid gpu (Intel + Nvidia GTX 1050ti) and after not getting audio through HDMI and trying every possibility (drm blacklist, neauveau blacklist etc...) I noticed MHWD makes an automatic file '/etc/udev/rules.d/90-mhwd-prime-powermanagement.rules' which contains the following line:

# Remove NVIDIA Audio devices, if present \n ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x040300", ATTR{remove}="1"

which causes the nvidia audio device to get disabled and not used. I am not sure if this is intended feature but I would suggest this to be given as a choice or properly documented as troubleshooting this audio issue took me many hours simply because as a novice user I was not aware of where and what to look for.

This issue exists regardless of whether intel igpu or nvidia is used as the primary card.

As a side note this issue does not exist on the live boot environment with nonfree drivers, although the line is also present there. As I could not find any difference between the config files of the live boot and installed version I am unsure whether this issue is the main culprit but regardless commenting this line caused my nvidia audio device to be properly recognized.

changed the description

changed the description

changed title from MHWD Automatically disables Audio on Nvidia PRIME Proprietary Driver to MHWD Automatically disables HDMI Audio on Nvidia PRIME Proprietary Driver

This is recommended by NVIDIA as

There is a known issue with the audio driver due to which the audio PCI function remains in an active state. This affects Linux kernel versions 4.19 (starting with git commit id 37a3a98ef601f89100e3bb657fb0e190b857028c ) through 5.4, and is fixed in Linux kernel version 5.5.

It could possibly be removed depending on the kernel version. Possibly the fix is even backported, which means it could be gotten rid of completely.

Solution would be to only apply it when the kernel is lower than 5.5

#!/bin/bash
currentver="$(uname -r | cut -c1-4)"
requiredver="5.5"
if [ "$(printf '%s\n' "$requiredver" "$currentver" | sort -V | head -n1)" = "$requiredver" ]; then 
        echo "Greater than or equal to ${requiredver}"
else
        echo "Less than ${requiredver}"
fi

Closing stale issue. Please feel free to reopen if the issue is still valid.

closed