No audio over DisplayPort MST
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Triaged
|
Medium
|
Unassigned |
Bug Description
I have a Lenovo ThinkPad E540 with an Intel Haswell (4th Gen) HD graphics controller connected to a OneLink Pro Dock. The Dock uses DisplayPort (DP) 1.2 MST (multi stream transport) to provide both a DP and a DVI port. My monitor is connected to the DP.
When I used kernels <= 3.16 audio worked fine, but the monitor would flicker heavily. So I installed linux-lts-vivid (3.19) which fixed the graphics problem (now I can see various DP? outputs in xrandr as opposed to one before), but there is no DP audio output to chose anymore.
I also tested the latest mainline kernel 4.1-rc8, where this bug still exists. To further investigate I got these version's kernel sources, applied 4 patches by Dave Airlie from the intel-gfx mailing list [1] and tested this build (4.1-rc8+), which fixed the problem! I can play sound over DP, the same way I can over HDMI or DP without MST.
I hope it is possible to backport these changes!
[1] haswell displayport MST audio support
http://
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.19.0-22-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Jun 21 01:44:30 2015
InstallationDate: Installed on 2014-01-06 (530 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
SourcePackage: linux-lts-vivid
UpgradeStatus: Upgraded to trusty on 2014-06-12 (373 days ago)
---
ApportVersion: 2.20.1-0ubuntu2.4
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
/dev/snd/
/dev/snd/
CurrentDesktop: Unity
DistroRelease: Ubuntu 16.04
HibernationDevice: RESUME=
InstallationDate: Installed on 2014-01-06 (1077 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: LENOVO 20C6S00200
NonfreeKernelMo
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=
ProcVersionSign
RelatedPackageV
linux-
linux-
linux-firmware 1.157.6
Tags: xenial
Uname: Linux 4.4.0-57-generic x86_64
UpgradeStatus: Upgraded to xenial on 2016-12-15 (3 days ago)
UserGroups: adm bumblebee cdrom dip lp lpadmin plugdev sambashare staff sudo vboxusers wireshark
_MarkForUpload: True
dmi.bios.date: 09/23/2016
dmi.bios.vendor: LENOVO
dmi.bios.version: J9ET9EWW (2.24 )
dmi.board.
dmi.board.name: 20C6S00200
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.
dmi.modalias: dmi:bvnLENOVO:
dmi.product.name: 20C6S00200
dmi.product.
dmi.sys.vendor: LENOVO
tags: | added: cherry-pick |
Changed in linux-lts-vivid (Ubuntu): | |
importance: | Undecided → Medium |
status: | Confirmed → Triaged |
tags: | added: latest-bios-2.24 |
Changed in linux (Ubuntu): | |
importance: | Low → Medium |
status: | Incomplete → Triaged |
tags: |
added: kernel-bug-exists-upstream-4.9 removed: kernel-bug-exists-upstream-4.1-rc8 latest-bios-2.24 |
tags: | added: kernel-bug-exists-upstream latest-bios-2.24 |
Status changed to 'Confirmed' because the bug affects multiple users.