Confirm this occurs with Dell AW17R3. Skylake i7 6700HQ with HM170 chipset and HD530 internal graphics controlling built in display and external Thunderbolt 3 to display port to HDMI adapter sound works good.
Discrete GPU is GTX 970M and on built-in HDMI port is hard wired to it (Optimus not supported). Here there is no sound and pavucontrol hangs can't even display configuration properly. Additional problem of about 40 pixels underscanning with both Nouveau and nVidia drivers. Windows 10 works perfectly in all departments except when resuming from an overnight suspend nVidia HDMI might have to be hot-plugged to fix screeching sound. Added NVMe Samsung Pro 960 M.2 SSD card meaning in Linux kernel hot plugging had to be deactivated due to known bug so solutions recommended above in that area will not work. Many thanks to previous poster for possible solution which I will hopefully have time to try in a couple weeks. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1377653 Title: HDMI sound output not detected / NVIDIA optimus laptop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1377653/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs