Another instance of this bug: https://www.reddit.com/r/archlinux/comments/ghozc1/cantt_get_audio_from_intel_graphics_hdmi_out/
Dear maintainers, maybe it's time to fix the IOMMU driver? Or, if IOMMU maintainers are indeed unreachable, maybe ALSA maintainers can detect this condition (iommu on, Haswell HDMI) and at least emit a warning in the log referencing this bug and a possible workaround? -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/1428121 Title: Intel HDMI Audio not working with IOMMU enabled Status in ALSA driver: Confirmed Status in alsa-driver package in Ubuntu: Confirmed Bug description: New ASRock Z97 Extreme 6 motherboard with an Intel i7 4790S and an Nvidia GTX 650. Host uses Intel IGD for video and HDMI audio out. When I pass kernel flags 'intel_iommu=on' or 'intel_iommu=on,igfx_on' HDMI audio no longer functions although the device and modules seem to load and I cannot locate any error messages. In this configuration IOMMU functions as expected and I can successfully pass the Nvidia card through to a KVM guest using VFIO. As per this (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1223840) bug report and the linked bugzilla thread I attempted to use kernel flag 'intel_iommu=on,igfx_off'. This resolves the HDMI audio out but breaks IOMMU as in VGA pass through generates DMA errors. I'm running from a clean installation of 14.10 with no modifications to the kernel or kvm, qemu, libvirt or virt-manager. In either scenario above the analogue audio out continues to function, I haven't tested the optical out as I have no hardware to do so. ProblemType: Bug DistroRelease: Ubuntu 14.10 Package: linux-image-3.16.0-31-generic 3.16.0-31.41 ProcVersionSignature: Ubuntu 3.16.0-31.41-generic 3.16.7-ckt5 Uname: Linux 3.16.0-31-generic x86_64 ApportVersion: 2.14.7-0ubuntu8.2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: kelvin 3468 F.... pulseaudio /dev/snd/controlC3: kelvin 3468 F.... pulseaudio /dev/snd/controlC0: kelvin 3468 F.... pulseaudio /dev/snd/controlC1: kelvin 3468 F.... pulseaudio CurrentDesktop: Unity Date: Wed Mar 4 12:53:17 2015 HibernationDevice: RESUME=UUID=4d35060a-85c4-45fd-9f8e-530491588931 InstallationDate: Installed on 2015-02-26 (5 days ago) InstallationMedia: Ubuntu-Server 14.10 "Utopic Unicorn" - Release amd64 (20141022.2) MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M. ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-31-generic.efi.signed root=UUID=4914f227-6bb0-40bb-a781-9ad7111a996f ro intremap=no_x2apic_optout intel_iommu=on,forcedac pci-stub.ids=10de:11c8,10de:0e0b nomdmonddf nomdmonisw RelatedPackageVersions: linux-restricted-modules-3.16.0-31-generic N/A linux-backports-modules-3.16.0-31-generic N/A linux-firmware 1.138.1 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/17/2014 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: P1.70 dmi.board.name: Z97 Extreme6 dmi.board.vendor: ASRock dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: To Be Filled By O.E.M. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP1.70:bd12/17/2014:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnZ97Extreme6:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.: dmi.product.name: To Be Filled By O.E.M. dmi.product.version: To Be Filled By O.E.M. dmi.sys.vendor: To Be Filled By O.E.M. To manage notifications about this bug go to: https://bugs.launchpad.net/alsa-driver/+bug/1428121/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
