I have the same N56VZ laptop running 14.04 as well, and can confirm this problem.
According to http://http.download.nvidia.com/XFree86/gpu-hdmi-audio- document/gpu-hdmi-audio.html#_verify_your_card_exists the nVidia card should show an audio device in lspci output if HDMI is connected and enabled. This doesn't happen on my laptop. I am using the proprietary 331 nvidia drivers and nvidia-prime *without* bumblebee. I can plugin an HDMI cable and the display automatically mirrors to the HDMI output, but no nVidia audio device is ever detected with lspci. NOTE: the snd_hda_codec_hdmi module doesn't load when I connect HDMI. Manually modprobing it loads the module but shows a 0 count for 'Used By' and no dmesg output. # lspci output with HDMI connected and screen mirrored to TV: 00:00.0 Host bridge: Intel Corporation 3rd Gen Core processor DRAM Controller (rev 09) 00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor PCI Express Root Port (rev 09) 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) 00:16.0 Communication controller: Intel Corporation 7 Series/C210 Series Chipset Family MEI Controller #1 (rev 04) 00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 (rev 04) 00:1b.0 Audio device: Intel Corporation 7 Series/C210 Series Chipset Family High Definition Audio Controller (rev 04) 00:1c.0 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 1 (rev c4) 00:1c.1 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 (rev c4) 00:1c.3 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 4 (rev c4) 00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 (rev 04) 00:1f.0 ISA bridge: Intel Corporation HM76 Express Chipset LPC Controller (rev 04) 00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04) 00:1f.3 SMBus: Intel Corporation 7 Series/C210 Series Chipset Family SMBus Controller (rev 04) 01:00.0 VGA compatible controller: NVIDIA Corporation GK107M [GeForce GT 650M] (rev a1) 03:00.0 Network controller: Qualcomm Atheros AR9485 Wireless Network Adapter (rev 01) 04:00.0 Ethernet controller: Qualcomm Atheros AR8161 Gigabit Ethernet (rev 10) # cat /proc/asound/cards output with HDMI connected: 0 [PCH ]: HDA-Intel - HDA Intel PCH HDA Intel PCH at 0xf7a00000 irq 44 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/1377653 Title: HDMI sound output not detected / NVIDIA optimus laptop Status in “alsa-driver” package in Ubuntu: New Bug description: Hi, not sure if this is an alsa or nvidia/nouveau bug. HDMI audio output doesn't appear in sound settings output panel. Audio works well on internal speakers, but it seems there is no way to make it output to hdmi... The laptop has optimus NVIDIA+Intel. The behaviour is the same with nouveau or nvidia proprietary driver. Please let me know if further testing is required ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: alsa-base 1.0.25+dfsg-0ubuntu4 ProcVersionSignature: Ubuntu 3.13.0-36.63-generic 3.13.11.6 Uname: Linux 3.13.0-36-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.14.1-0ubuntu3.5 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: sam 2295 F.... pulseaudio CurrentDesktop: Unity CurrentDmesg: Error: command ['sh', '-c', 'dmesg | comm -13 --nocheck-order /var/log/dmesg -'] failed with exit code 1: comm: /var/log/dmesg: Permission denied Date: Sun Oct 5 17:05:35 2014 InstallationDate: Installed on 2014-04-21 (166 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) PackageArchitecture: all SourcePackage: alsa-driver Symptom: audio Title: PCI/internal sound card not detected UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 11/02/2012 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: N56VZ.215 dmi.board.asset.tag: ATN12345678901234567 dmi.board.name: N56VZ dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: 1.0 dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: ASUSTeK COMPUTER INC. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrN56VZ.215:bd11/02/2012:svnASUSTeKCOMPUTERINC.:pnN56VZ:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnN56VZ:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0: dmi.product.name: N56VZ dmi.product.version: 1.0 dmi.sys.vendor: ASUSTeK COMPUTER INC. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1377653/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
