[alsa-devel] Headset doesn't work for HP EliteBook 755 G2

[Takashi Iwai]

On Tue, 23 Feb 2016 21:02:17 +0100,
Derick Eddington wrote:
> 
> Hi, first time here, following suggestion [1] to report non-working
> default configuration, which I found how to make work.
> 
> I checked using the latest stable kernel 4.4.2 and my headset jack
> doesn't work by default but my fix does work, on Scientific Linux 7.2
> using the 4.4.2 kernel from the ELRepo repository.  I also checked using
> Ubuntu 16.04 alpha with its 4.4.0 kernel and the problem and fix are the
> same.
> 
> My laptop is an HP EliteBook 755 G2 from mid 2015 [2] that has a
> combined headset (headphone + mic) jack that doesn't work by default.
> The speakers work fine by default and they mute when a headset is
> plugged in, but the headphones don't work.
> 
> The snd-hda-intel module handles my device.
> The codec is Realtek ALC3228.
> I have the latest BIOS update from HP.
> 
> I got it working by passing model=hp,headset-mic to snd-hda-intel.  I
> found this fix in an alsa-user message about a different HP laptop with
> the same codec [3], but I had to modify the message's fix by only
> including the module option for model= and omitting the other options
> and aliases that seem to be specific to Arch Linux.  I tried using only
> "hp" or only "headset-mic" as the value for model= but neither worked.

The point is the comma.  Your Realtek codec is assigned as the
secondary, and model option takes multiple values, one for each slot.
So, you'd need to pass "model=,headset-mic"

> Attached are my outputs of alsa-info.sh from before and after I did
> model=hp,headset-mic.

Thanks, I'll compare them.  Isn't the any functionality lost by this
option?  Everything (except for the noise issue) works by that?

> Also, there's another problem after enabling model=hp,headset-mic, which
> I found how to fix:  There is a very annoying squeaky background noise in
> the headphones that's independent of adjusting the volume level but it
> does stop when the headphones are muted.  I tried a different headset
> and it's the same.  I found how to suppress this by using the
> white_noise_fix.py script from [4] as described at [5,6], which
> apparently does some ioctl verbs to adjust the amp gain.  I thought this
> might be something that should be fixed/adjusted in the kernel module(s)
> that handle this device, so that the white_noise_fix.py isn't needed.
> If so, maybe it's worth mentioning that when my laptop resumes from
> sleep, the background noise comes back, so I have to run
> white_noise_fix.py again.

Such a noise often comes from the analog-loopback.  Try to turn off
"Loopback Mixing" mixer switch.


Takashi