8086:0412 Intel HDMI Audio not working with IOMMU enabled

[Andreas Egli]

Using Saucy Development I noticed the HDMI audio output of the intel graphics stops working if IOMMU is enabled via kernel boot parameter intel_iommu=on. I need the IOMMU to pass an ATI graphics card to a qemu virtual machine.

WORKAROUND: If the IOMMU is disabled, everything works fine.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-7-generic 3.11.0-7.13
ProcVersionSignature: Ubuntu 3.11.0-7.13-generic 3.11.0
Uname: Linux 3.11.0-7-generic x86_64
ApportVersion: 2.12.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: htpc 2602 F.... pulseaudio
 /dev/snd/controlC0: htpc 2602 F.... pulseaudio
Date: Wed Sep 11 14:00:38 2013
InstallationDate: Installed on 2013-07-19 (54 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
IwConfig:
 br0 no wireless extensions.

 eth2 no wireless extensions.

 lo no wireless extensions.
MachineType: ASUS All Series
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.11.0-7-generic root=/dev/mapper/local_system-linux ro quiet splash intel_iommu=on pcie_acs_override=downstream vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-7-generic N/A
 linux-backports-modules-3.11.0-7-generic N/A
 linux-firmware 1.113
RfKill:

SourcePackage: linux
UpgradeStatus: Upgraded to saucy on 2013-07-22 (50 days ago)
dmi.bios.date: 08/19/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1405
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: SABERTOOTH Z87
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1405:bd08/19/2013:svnASUS:pnAllSeries:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnSABERTOOTHZ87:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: All Series
dmi.product.version: System Version
dmi.sys.vendor: ASUS

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a kernel version where you were not having this particular problem? This will help determine if the problem you are seeing is the result of the introduction of a regression, and when this regression was introduced. If this is a regression, we can perform a kernel bisect to identify the commit that introduced the problem.

[Andreas Egli (kharan-kangon)]

I just tested the current raring kernel (3.8.0-30) which exhibits the same behavior. Therefore I would say that it is not a regression.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.11 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11-saucy/

[Andreas Egli (kharan-kangon)]

The latest upstream kernel 3.11.0-031100-generic also has the problem.

[Joseph Salisbury (jsalisbury)]

This issue appears to be an upstream bug, since you tested the latest upstream kernel. Would it be possible for you to open an upstream bug report[0]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.

Please follow the instructions on the wiki page[0]. The first step is to email the appropriate mailing list. If no response is received, then a bug may be opened on bugzilla.kernel.org.

Once this bug is reported upstream, please add the tag: 'kernel-bug-reported-upstream'.

[0] https://wiki.ubuntu.com/Bugs/Upstream/kernel

[penalvch (penalvch)]

Andreas Egli, as per upstream https://bugzilla.kernel.org/show_bug.cgi?id=61471#c14 this is a firmware (BIOS) bug. When you contacted Asus and/or Intel about this, what was their response?

[Kelvin Middleton (kelvin-middleton)]

I know this is an old bug but I have the same issue with a new ASRock Z97 Extreme 6 with an i7 4790S. I've reviewed the linked bugzilla report from post #8 and the *fix* to use 'intel_iommu=on,igfx_off' does indeed allow audio to resume but breaks IOMMU as in I can no long pass through my Nvidia GTX 650 card to a KVM guest. As the bugzilla bug is marked WONTFIX due to a firmware issue I wondered where this now stands with the same problem spanning 2 different vendors i.e. ASUS in the original 2013 and my ASRock today?

[penalvch (penalvch)]

Kelvin Middleton, bugzilla is legacy, and not necessarily the final authority. However, it would help immensely if you filed a new report via a terminal:
ubuntu-bug linux

Please feel free to subscribe me to it.

[Kelvin Middleton (kelvin-middleton)]

Thanks for the steer Christopher, I've filed a new report and subscribed you.

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1428121