Guys, I have a NUC PC that had Ubuntu 23.10, installed from scratch, and everything worked, including the Audio via the HDMI Port.
After updating it to Ubuntu 24.04, The HDMI Audio stopped working. I've seen reports from other users with the same problem.
I've already tried to edit the file "/etc/default/grub" and insert the line "intel_iommu=on,igfx_off" in it, but it still doesn't work.



Additional information follows:
lcarlin@LDA0269:~$ lspci | grep udio
00:1f.3 Audio device: Intel Corporation Alder Lake-N PCH High Definition Audio Controller
lcarlin@LDA0269:~$


carlin@LDA0269:~$ aplay -l
**** Lista de Dispositivos PLAYBACK Hardware ****
placa 0: PCH [HDA Intel PCH], dispositivo 3: HDMI 0 [AOC LCD]
Dispositivo secundário: 1/1
Dispositivo secundário #0: subdevice #0
placa 0: PCH [HDA Intel PCH], dispositivo 7: HDMI 1 [HDMI 1]
Dispositivo secundário: 1/1
Dispositivo secundário #0: subdevice #0
placa 0: PCH [HDA Intel PCH], dispositivo 8: HDMI 2 [HDMI 2]
Dispositivo secundário: 1/1
Dispositivo secundário #0: subdevice #0
placa 0: PCH [HDA Intel PCH], dispositivo 9: HDMI 3 [HDMI 3]
Dispositivo secundário: 1/1
Dispositivo secundário #0: subdevice #0
placa 1: HID [USB Audio and HID], dispositivo 0: USB Audio [USB Audio]
Dispositivo secundário: 1/1
Dispositivo secundário #0: subdevice #0
lcarlin@LDA0269:~$




lcarlin@LDA0269:~$ cat /proc/asound/cards
0 [PCH ]: HDA-Intel - HDA Intel PCH
HDA Intel PCH at 0x6001110000 irq 134
1 [HID ]: USB-Audio - USB Audio and HID
CSCTEK USB Audio and HID at usb-0000:00:14.0-6, full speed
lcarlin@LDA0269:~$


lcarlin@LDA0269:~$ sudo alsa force-reload
Unloading ALSA sound driver modules: snd-seq-midi snd-seq-midi-event snd-sof-pci-intel-tgl snd-sof-intel-hda-common snd-sof-intel-hda snd-sof-pci snd-sof-xtensa-dsp snd-sof snd-sof-utils snd-soc-hdac-hda snd-soc-acpi-intel-match snd-soc-acpi snd-seq-dummy snd-hrtimer snd-sof-intel-hda-mlink snd-hda-ext-core snd-soc-core snd-compress snd-hda-codec-hdmi snd-pcm-dmaengine snd-usb-audio snd-hda-intel snd-intel-dspcfg snd-intel-sdw-acpi snd-hda-codec snd-usbmidi-lib snd-hda-core snd-hwdep snd-ump snd-pcm snd-rawmidi snd-seq snd-seq-device snd-timer (failed: modules still loaded: snd-hrtimer snd-sof-intel-hda-mlink snd-hda-ext-core snd-soc-core snd-compress snd-hda-codec-hdmi snd-pcm-dmaengine snd-usb-audio snd-hda-intel snd-intel-dspcfg snd-intel-sdw-acpi snd-hda-codec snd-usbmidi-lib snd-hda-core snd-hwdep snd-ump snd-pcm snd-rawmidi snd-seq snd-seq-device snd-timer).
Loading ALSA sound driver modules: snd-seq-midi snd-seq-midi-event snd-sof-pci-intel-tgl snd-sof-intel-hda-common snd-sof-intel-hda snd-sof-pci snd-sof-xtensa-dsp snd-sof snd-sof-utils snd-soc-hdac-hda snd-soc-acpi-intel-match snd-soc-acpi snd-seq-dummy snd-hrtimer snd-sof-intel-hda-mlink snd-hda-ext-core snd-soc-core snd-compress snd-hda-codec-hdmi snd-pcm-dmaengine snd-usb-audio snd-hda-intel snd-intel-dspcfg snd-intel-sdw-acpi snd-hda-codec snd-usbmidi-lib snd-hda-core snd-hwdep snd-ump snd-pcm snd-rawmidi snd-seq snd-seq-device snd-timer.
lcarlin@LDA0269:~$


lcarlin@LDA0269:~$ sudo systemctl --now --user restart pipewire pipewire-pulse
Failed to connect to bus: Mídia não encontrada
lcarlin@LDA0269:~$


lcarlin@LDA0269:/var/log$ lspci -nnk | grep -n -A 4 -i Audio
43:00:1f.3 Audio device [0403]: Intel Corporation Alder Lake-N PCH High Definition Audio Controller [8086:54c8]
44- DeviceName: Onboard - Sound
45- Subsystem: Intel Corporation Device [8086:7270]
46- Kernel driver in use: snd_hda_intel
47- Kernel modules: snd_hda_intel, snd_sof_pci_intel_tgl
lcarlin@LDA0269:/var/log$


lcarlin@LDA0269:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 24.04 LTS
Release: 24.04
Codename: noble
lcarlin@LDA0269:~$


If you need any more information about my system, please write to me.
I've been having this problem since I updated and I don't know how to solve it! you are my only hope!