http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16.36-trusty/ is the latest working kernel http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16.39 for example won't work
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-lts-vivid in Ubuntu. https://bugs.launchpad.net/bugs/1467190 Title: No audio over DisplayPort MST Status in linux-lts-vivid package in Ubuntu: Triaged 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://www.spinics.net/lists/intel-gfx/msg68973.html ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.19.0-22-generic 3.19.0-22.22~14.04.1 ProcVersionSignature: Ubuntu 3.19.0-22.22~14.04.1-generic 3.19.8-ckt1 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) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-vivid/+bug/1467190/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
