[MS-7721, ATI R6xx HDMI, Digital Out, HDMI] No sound at all

[Arvin]

no sound after upgrade

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 3.13.0-49.83-generic 3.13.11-ckt17
Uname: Linux 3.13.0-49-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: arvin 8424 F.... pulseaudio
 /dev/snd/controlC0: arvin 8424 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Aug 2 10:08:20 2016
InstallationDate: Installed on 2015-04-20 (469 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:HDMI failed
Symptom_Card: Built-in Audio - HDA ATI HDMI
Symptom_DevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: arvin 8424 F.... pulseaudio
 /dev/snd/controlC0: arvin 8424 F.... pulseaudio
Symptom_Jack: Digital Out, HDMI
Symptom_Type: No sound at all
Title: [MS-7721, ATI R6xx HDMI, Digital Out, HDMI] No sound at all
UpgradeStatus: Upgraded to xenial on 2016-07-31 (1 days ago)
dmi.bios.date: 12/16/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: V32.1
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: A55M-E33 (MS-7721)
dmi.board.vendor: MSI
dmi.board.version: 7.0
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: 7.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrV32.1:bd12/16/2013:svnMSI:pnMS-7721:pvr7.0:rvnMSI:rnA55M-E33(MS-7721):rvr7.0:cvnToBeFilledByO.E.M.:ct3:cvr7.0:
dmi.product.name: MS-7721
dmi.product.version: 7.0
dmi.sys.vendor: MSI