Thanks for the steer Christopher, I've filed a new report and subscribed you.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1428121 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1223840 Title: 8086:0412 Intel HDMI Audio not working with IOMMU enabled To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1223840/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs