Comment 30 for bug 1851518

I have been trying to get ALC298 working for a while now and wanted to share my findings. This issue exist on all distros and is an ALSA problem (not pulseaudio). Verified it when found a fix for the headphone by using the kernel's early patching feature. To use this feature, write a simple patch (instructions here https://www.kernel.org/doc/html/v5.0/sound/hd-audio/notes.html):

[codec]
0x10ec0298 0x144dc169 0

[model]
auto

[verb]
0x1a 0x707 0xc5

and save it as /lib/firmware/alc298-sound-patch.fw then save:

options snd-hda-intel patch=alc298-sound-patch.fw,alc298-sound-patch.fw,alc298-sound-patch.fw,alc298-sound-patch.fw

to /etc/modprobe.d/alc298-sound-patch.conf

Then reboot the machine and try your headphones. Next speakers! unfortunately all three mixer pins in the hda codec are set to mute and I'm working like a maniac to find a way of unmuting them, hoping that would fix the speakers. Hope this helps someone.

Went from web development to system development over this issue. Some may call that progress!