No sound card detected on Dell Vostro 5568 (17.04)

Question

I've install Kubuntu 17.04 on Dell Vostro 5568 with encrypted filesystem. The laptop comes with UEFI bios. In order to install nvidia drivers I had to disable secure UEFI boot. After turning laptop off and on again the sound card stopped working. The whole hard drive is on encrypted LVM.

$ lspci -v | grep -A7 -i "audio"
00:1f.3 Audio device: Intel Corporation Device 9d71 (rev 21)
        Subsystem: Dell Device 0786
        Flags: bus master, fast devsel, latency 32, IRQ 16
        Memory at d5228000 (64-bit, non-prefetchable) [size=16K]
        Memory at d5200000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [50] Power Management version 3
        Capabilities: [60] MSI: Enable- Count=1/1 Maskable- 64bit+
        Kernel driver in use: snd_hda_intel

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Currently the only audio output device is "Dummy output". Funny enough after suspending laptop to hibernation and waking it up the sound card device appears correctly:

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC3246 Analog [ALC3246 Analog]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

I'm a bit suspicious about the combination of encrypted filesystem and UEFI boot that might cause problems with detecting hardware.

$ cat /proc/asound/card0/codec* | grep Codec
Codec: Realtek ALC3246
Codec: Intel Kabylake HDMI

Alsa manual does not explicitly state that Realtek ALC3246 card is supported but as the card sometimes works and sometimes there's no sound device at all I'm not sure whether it's still a software issue.

EDIT: After reboot the sound card is gone again. I've tried disabling and enabling sound card in BIOS without any success.

Answer 1

It look like aplay detects a Alsa audio device so the problem could be the Pulseaudio layer (which runs on top of Alsa audio driver layer) .

To reset pulseaudio parameters, run this command in a terminal:

mv ~/.pulse/ ~/.pulsebak

killall pulseaudio

then test.

Also you can install pavucontrol package ("pulseaudio volume control") to have more controls on pulseaudio.

Answer 2

I went to BIOS and reset settings to factory defaults. After rebooting speakers and microphone were immediately found. I've also forced kernel module loading:

sudo echo "snd_hda_intel" >> /etc/modules

Though the problem seems to be quite random, usually sound card is not found after reboot, but only after waking from hibernation.

Answer 3

The only thing that worked with my wife's the Dell Vostro 5568 was to

1. in the BIOS switch audio off and save
2. reboot to BIOS
3. switch audio on again, save and boot

This is a better solution than resetting all BIOS settings to the factory defaults. Hit the F2 key when the laptop starts booting to enter the BIOS settings. This is from a similar askubuntu issue, https://askubuntu.com/a/924499/512264. User Sy Langbein used this method to get sound working on a Dell Vostro 5568.

EDIT: Just realized that this issue is for Ubuntu 17.04, my wife's laptop is running 16.04.