Mute LED doesn't light on with HP Laptop 15-dw0xxx.

[F_Adrien]

Hello,

We recently bought a HP Laptop 15-dw0105nf (85EF) with Xubuntu 20.04 installed on. This is the only OS installed on the computer (the audio card is a Realtek ALC236, searching on Internet I haven't found any technical information about it, and most of the time, only Windows drivers...).

Then, in the next few days, I've met a weird thing: the Mute LED, present on the F6 key is not lighting on when Mute button is pressed (even if the sound is muting and works well), it stills always off. So I decided to update the BIOS (perhaps the problem was there) but even after the update (the actual version is F.30) the problem still persist.

After searching on some forums where the problem can come from, I've been aware that this LED is controlled by some PIN of the audio card (and so, solving the issue remain essentially in finding out the right values). The real problem is that I haven't any working cases, no examples where the LED is working and thus I cannot compare the values set by my OS to the right ones (in most cases, users solved the issue by comparing their values to the right ones which is oftenly provided by Windows). Moreover, trials-and-error seems a (very) bad approach.

Also, I've noticed (using the dmidecode  command) in the OEM string the following: [...] String 6: HP_Mute_LED_P_G [...] 
where P and G are values (concerning the Mute LED) that must be specified by the BIOS. But in my case, they are not (this shows that the BIOS is buggy...).

Well, here is a link to some information concerning my audio codec: http://alsa-project.org/db/?f=0d2571ad73f7a63ecf60a380c3374590c6a57a51

Thanks for you attention and your patience.