Sound over HDMI is 2x as slow after resuming from standby

[Dan Dascalescu]

I have an extremely frustrating problem with Ubuntu 16.04.1 LTS 64-bits on my Dell E7450 laptop: when I connect a TV over HDMI afater resuming from standby, the sound is 2x as slow, and everything else, e.g. video playback, is dragged down to slow-motion.

For example, testing audio via Speaker Testing goes "Frooont Leeeft" in a low-pitch male voice (the normal is a crisp "Front Left" in a female voice").

Reproduction steps:

1. Connect laptop to TV over HDMI cable
2. Go to All Settings -> Sound and select to "Play sound through" HDMI/DisplayPort audio
3. Play a video and ensure the playback is at normal speed and the sound comes out of the TV.
4. Suspend the laptop.
5. Resume the laptop.
6. Play the same video again.

Actual results: the sound and video look slow-motion, at about 50% speed. Go to Test Sound, and Front Left will sound like "Frooont Leeeft".

This is super annoying because I have to close all my applications and reboot every time I want to watch a movie through my TV.

Asked at http://askubuntu.com/questions/805355/sound-over-hdmi-is-2x-as-slow-after-resuming-from-standby, no luck.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity-control-center 15.04.0+16.04.20160705-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-36.55-generic 4.4.16
Uname: Linux 4.4.0-36-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Sep 4 22:31:04 2016
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/unity-control-center
InstallationDate: Installed on 2016-09-04 (1 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: unity-control-center
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[eddy (eddddandrews)]

Similar problem for me on Intel NUC. Sometimes this problem, sometimes no sound at all.
Also, and sometimes, there is no sound on initial boot, which is sometimes fixed by going to sound test and starting a test