Audio workaround and fixes with PipeWire

jaymz665 did amazing work and shared it in the Matrix room to improve the stability and noise of SDM845 audio stack.

Changes

sudo rm -r /etc/wireplumber/main.lua.d

sudo nano /etc/wireplumber/wireplumber.conf.d/51-disable-suspension.conf
monitor.alsa.rules = [
  {
    matches = [
      {
        # Matches all sources
        node.name = "~alsa_input.*"
      },
      {
        # Matches all sinks
        node.name = "~alsa_output.*"
      }
    ]
    actions = {
      update-props = {
        audio.format           = "S16LE"
        audio.rate             = 48000
        api.alsa.period-size   = 4096
        api.alsa.period-num    = 6
        api.alsa.headroom      = 512,
       # session.suspend-timeout-seconds = 0
       # dither.method = "wannamaker3", # add dither of desired shape
       # dither.noise = 2, # add additional bits of noise
     }
    }
  }
]

sudo nano  /usr/sbin/call_audio_idle_suspend_workaround

#!/bin/sh

# dbus-monitor is run as a child process to this script. Kill child process too when the script terminates.
trap 'pkill -9 -P $$ && exit 0' INT TERM

interface=org.freedesktop.ModemManager1.Call
member=StateChanged

dbus-monitor --system "type='signal',interface='$interface',member='$member'" |
        while read -r line; do
                state=$(echo "$line" | awk '/\<int32\>/ {print $2}')
                if [ -n "$state" ]; then
                        # Call State is based on https://www.freedesktop.org/software/ModemManager/doc/latest/ModemManager/ModemManager-Flags-and-Enumerations.html#MMCallState
                        if [ "$state" -eq '0' ] || [ "$state" -eq '3' ]; then
                                echo "Call Started"
                                alsaucm reload
                                pw-loopback &

                                # Unload module-suspend-on-idle when call begins
                                #pactl unload-module module-suspend-on-idle
                        fi

                        if [ "$state" -eq '7' ]; then
                                echo "Call Ended"
                                killall -9 pw-loopback &

                                # Reload module-suspend-on-idle after call ends
                                #pactl load-module module-suspend-on-idle
                        fi
                fi
        done &

wait