[Bug 1901922] Re: [SRU][Lenovo ThinkPad T14 Gen 1] No sound output device on startup

[Maxime Lemonnier]

I  have a T14 AMD, running kubuntu 20.04-2, I have alsa-lib -
1.2.2-2.1ubuntu2.3 installed.

Nothig seems wrong with my sound config until I try playing a sound. It
then glitches like hell (repeating the same note at 2-4Hz)

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Title:
  [SRU][Lenovo ThinkPad T14 Gen 1] No sound output device on startup

Status in ALSA Libraries:
  Fix Released
Status in alsa-lib package in Ubuntu:
  Fix Released
Status in alsa-ucm-conf package in Ubuntu:
  Fix Released
Status in alsa-lib source package in Focal:
  Fix Released
Status in alsa-ucm-conf source package in Focal:
  Fix Released
Status in alsa-lib source package in Groovy:
  Fix Released
Status in alsa-ucm-conf source package in Groovy:
  Fix Released
Status in alsa-lib source package in Hirsute:
  Fix Released
Status in alsa-ucm-conf source package in Hirsute:
  Fix Released

Bug description:
  [Impact]
  On the machines with AMD Ryzen acp audio design, the audio can't work
  anymore after upgrading the libasound2 to ubuntu3(groovy)/ubuntu2.1(
  focal), this is a regression on libasound2 for those machines. the AMD
  Ryzen acp audio card needs to load ucm to work with pulseaudio, but
  this audio card doesn't have an independant ucm for it, it needs to
  link to an existing HDA-Intel ucm, the check_empty_configuration() needs
  to cover the situation that Linked is true, otherwise it will fail
  to load the ucm for the audio card. Even the audio card could load the
  ucm, the output is muted and the init output volume is too low if
  freshly install the OS on these machines.

  [Fix]
  Backport 1 alsa-lib patch to fix the failure of loading ucm on AMD
  Ryzen acp audio machines. Backport 4 alsa-ucm-conf patches to fix
  init mute and init output volume problem.

  [Test Case]
  Install the updated libasuond2, rm ~/.config/pulse/*; sudo rm -rf
  /var/lib/alsa/*; sudo sh -c 'echo b > /proc/sysrq-trigger' and run pacmd
  list-cards, we could see the pulseaudio load the ucm successfully and we could see
  the sound card is generated and all output and input devices are listed
  under sound card, but the init output is muted and the volume is very low
  if we manually unumte it. Now install the updated alsa-ucm-conf, rm ~/.config/pulse/*; sudo rm -rf
  /var/lib/alsa/*; sudo sh -c 'echo b > /proc/sysrq-trigger', the output is
  not muted anymore and the output volume is OK to most users.

  [Regression Risk]
  This could make the machines with sof audio driver fail to load ucm
  , then all audio function can't work as before, like the speaker can't
  output sound or the internal mic can't be found or can't record sound.
  But this possibility is very low, I tested this SRU on some machines with or
  without sof audio driver, all worked as well as before.

  
  After logging in, only a dummy device is available for audio playback (resulting in no audible playback). When running "pactl load-module module-detect" the sound card shows up, and playback works as expected.

  If pulseaudio is restarted with "pulseaudio -k" the playback device
  disappears again. Running the above command get things working again.

  If I change the following section in /etc/pulse/default.pa from:

  ### Automatically load driver modules depending on the hardware available
  .ifexists module-udev-detect.so
  load-module module-udev-detect
  .else
  ### Use the static hardware detection module (for systems that lack udev support)
  load-module module-detect
  .endif

  To:

  ### Automatically load driver modules depending on the hardware available
  #.ifexists module-udev-detect.so
  #load-module module-udev-detect
  #.else
  ### Use the static hardware detection module (for systems that lack udev support)
  load-module module-detect
  #.endif

  Things start working as they should after running "pulseaudio -k".

  ProblemType: Bug
  DistroRelease: Ubuntu 20.10
  Package: pulseaudio 1:13.99.2-1ubuntu1
  ProcVersionSignature: Ubuntu 5.8.0-26.27-generic 5.8.14
  Uname: Linux 5.8.0-26-generic x86_64
  ApportVersion: 2.20.11-0ubuntu50
  Architecture: amd64
  CasperMD5CheckResult: skip
  CurrentDesktop: KDE
  Date: Wed Oct 28 17:21:02 2020
  InstallationDate: Installed on 2020-10-23 (4 days ago)
  InstallationMedia: Kubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
  SourcePackage: pulseaudio
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 08/07/2020
  dmi.bios.release: 1.9
  dmi.bios.vendor: LENOVO
  dmi.bios.version: R1BET40W(1.09 )
  dmi.board.asset.tag: Not Available
  dmi.board.name: 20UDCTO1WW
  dmi.board.vendor: LENOVO
  dmi.board.version: Not Defined
  dmi.chassis.asset.tag: No Asset Information
  dmi.chassis.type: 10
  dmi.chassis.vendor: LENOVO
  dmi.chassis.version: None
  dmi.ec.firmware.release: 1.9
  dmi.modalias: dmi:bvnLENOVO:bvrR1BET40W(1.09):bd08/07/2020:br1.9:efr1.9:svnLENOVO:pn20UDCTO1WW:pvrThinkPadT14Gen1:rvnLENOVO:rn20UDCTO1WW:rvrNotDefined:cvnLENOVO:ct10:cvrNone:
  dmi.product.family: ThinkPad T14 Gen 1
  dmi.product.name: 20UDCTO1WW
  dmi.product.sku: LENOVO_MT_20UD_BU_Think_FM_ThinkPad T14 Gen 1
  dmi.product.version: ThinkPad T14 Gen 1
  dmi.sys.vendor: LENOVO

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