Bug 94804

Summary:	Major audio-video sync and audio dropout problems when using Intel HDMI audio
Product:	DRI	Reporter:	Robert Hancock <hancockrwd>
Component:	DRM/Intel	Assignee:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Status:	RESOLVED MOVED	QA Contact:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity:	major
Priority:	medium	CC:	intel-gfx-bugs, lennart
Version:	unspecified
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description Robert Hancock 2016-04-03 01:41:01 UTC

I've got a machine using Intel Haswell integrated video with the HDMI1 output connected to a monitor and HDMI2 connected to a Yamaha RX-V577 AV receiver which is connected to a TV. This is using Fedora 23 and pulseaudio-7.1-1.fc23.x86_64.

Whenever I have the audio output routed to "HDMI/DisplayPort 2" and try to play a video in Firefox or Totem, the video appears to run too fast and the audio becomes up to several seconds behind the video. The audio also keeps playing for several seconds when pausing the video. When playing a video file in VLC, it doesn't lose sync as much, but the audio cuts in and out, and in the VLC debug log it has lots of complaints like this:

pulse debug: changing sink 2: alsa_output.pci-0000_00_03.0.hdmi-surround-extra1 (Built-in Audio Digital Surround 5.1 (HDMI 2))
pulse debug: started
core warning: picture is too late to be displayed (missing 25 ms)
core debug: picture might be displayed late (missing 13 ms)
core warning: playback way too early (-121209): playing silence
core debug: inserting 5818 zeroes
core warning: playback too early (-40158): down-sampling
core warning: timing screwed (drift: -81704 us): stopping resampling
core warning: playback too early (-82366): down-sampling
core warning: playback way too early (-121032): playing silence
core debug: inserting 5809 zeroes
core debug: auto hiding mouse cursor
core warning: playback too early (-40230): down-sampling
core debug: auto hiding mouse cursor
core warning: timing screwed (drift: -80762 us): stopping resampling
core warning: playback too early (-81447): down-sampling
core warning: playback way too early (-120541): playing silence
core debug: inserting 5785 zeroes

VLC's audio output appears to work properly if I run VLC under pasuspender and configure it to use ALSA audio output instead, so it seems like this is a PulseAudio problem.

Not sure what more to do to debug this. I can provide more info if needed.

Comment 1 Raymond 2016-04-03 03:23:20 UTC

Post the output of alsa-info.sh

xrandr --verbose




Aud_Synch_Delay[7:0]  indicates  the amount  of  latency  added by  the  sink.  It  is  expressed in  terms of  units  of  2 ms of  delay  of  video compared  to audio  for  the  given video mode being  driven on the link

Comment 2 Alexander E. Patrakov 2016-04-03 06:44:56 UTC

Haswell HDMI audio users are affected by a longstanding kernel IOMMU bug: https://bugzilla.kernel.org/show_bug.cgi?id=60769 . To make sure that your report is not a duplicate, please add the following kernel command line option and reboot:

    intel_iommu=on,igfx_off

If that alone doesn't help, please try:

    intel_iommu=on,igfx_off snd_hda_intel.align_buffer_size=1

Comment 3 Robert Hancock 2016-04-07 00:45:23 UTC

It looks like "intel_iommu=on,igfx_off" does resolve the problem. Will add a note to the referenced kernel bug report.

Comment 4 Martin Peres 2019-11-29 17:14:55 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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