Fixup NVIDIA audio device power state when HDMI screen is attached or removed

nvhda-fixup.sh

#!/bin/bash

NVHDA_FILE="/proc/acpi/nvhda"

# Check all HDMI connections
while IFS= read -r; do
    DRIVER=$(realpath "$(dirname "$REPLY")"/../device/driver)
    if [ "$(basename "$DRIVER")" = "nvidia" ]; then
        HDMI_CONNECTED=1
        break
    fi
done < <(grep -l ^connected /sys/class/drm/*HDMI*/status)

NVHDA_STATUS="$(cat $NVHDA_FILE)"
NVHDA_STATUS="${NVHDA_STATUS##* }"
if [ -n "$HDMI_CONNECTED" ] && [ "$NVHDA_STATUS" == "OFF" ]; then
    echo "ON" > "$NVHDA_FILE"
    echo "HDA NVidia: turned on"
elif [ -z "$HDMI_CONNECTED" ] && [ "$NVHDA_STATUS" == "ON" ]; then
    echo "OFF" > "$NVHDA_FILE"
    echo "HDA NVidia: turned off"
fi