No microphone input signal while sound still works

[staskhudzik]

Note that there is a bug report on no sound on Samsung chromebooks which may or may not be similar to your issue

https://www.mail-archive.com/kernel-...msg398292.html

Sorry cannot be of any further help.

It may be, though from what I've seen it does not deal with mic in particular. Again, thanks for the suggestion. At at least now I'm fully convinced that that the soundcard on Sumsung chromebooks is ass)

Also, the issue might be connected with system seeing two soundcards. Few minutes ago I attempted to use
alsamixer -c 0 sset 'Mic',0 100% cap unmute
alsamixer -c 0 sset 'Mic Boost (+20dB)',0 on

and the result was that alsamixer displayed the mixer for HDA Intel PCH with no parameters being modifiable instead of chtrt5650.
here's how it looked like: https://imgur.com/Q0dVBEs.png

[gdesilva]

According to lspci there is only one sound device which is HDA Intel PCH. I may be wrong here but Braswell HDMI refers to this sound device built in on the Braswell mobo.

Is there a separate HDMI IN port on your system?

EDIT: check that you have defined the correct profile for the HDMI Audio - if it can handle two way (both output and input) then the profile should be something like Digital Stereo Duplex in pavucontrol->Configuration

[gdesilva]

Did a bit of digging into these Chromebooks and it appears that audio on these things running Linux is a known problem. As MrChromebox says, "Then you have to deal with potentially porting functionality/drivers from ChromeOS to the upstream Linux kernel, because there's zero chance everything works out of the box (especially audio)." in https://www.reddit.com/r/chromeos/co...xy_chromebook/

[staskhudzik]

According to lspci there is only one sound device which is HDA Intel PCH. I may be wrong here but Braswell HDMI refers to this sound device built in on the Braswell mobo.

Is there a separate HDMI IN port on your system?

EDIT: check that you have defined the correct profile for the HDMI Audio - if it can handle two way (both output and input) then the profile should be something like Digital Stereo Duplex in pavucontrol->Configuration

What do you mean by "on my system"? According to pavucontrol my profile was stereo output + multi-channel input. I tried switching it to multi-channel duplex but nothing really changed.

[gdesilva]

What I meant was whether you have two HDMI ports, HDMI IN and HDMI out - unlikely but thought of checking it anyway.

Perhaps, someone with experience with Chromebooks can suggest a solution or a workaround this issue.

[staskhudzik]

What I meant was whether you have two HDMI ports, HDMI IN and HDMI out - unlikely but thought of checking it anyway.

I have a one port.

Today I decided to mess with alsamixer a bit more and tried unmuting everything possible. After the operation the mic turned on but with an extremely loud hiss. I started tweaking knobs to figure which one was responsible for mic and somehow messed the whole sound. Now even output signal is off, in the pavucontrol there are only dummy input and output and the sound does not react to alsamixer at all.
The good thing that after upgrade alsamixer allows to display multiple parameters in terminal. Now, however, this is not a big help, I guess(

[gdesilva]

If I were you, I would try re-installing alsa sound but given there appears to be an underlying issue with sound on Chromebooks it may not fix your issue - still worth a try now that it is all broken anyway!

[TheFu]

I've had 2 chromebooks. Put ubuntu on both. Sound always worked on both, though did use a usb mic to get better input audio for recordings. The audio jack on my toshiba chromebook was always a mystery. The usb mic solved all sorts of issues for me. Samson GoMic.

Never had any special audio issues with my Haswell 2995U chromebook.
Never had any special audio issues with my Broadwell 5015U chromebook.

The only issue I had with either was low RAM (expected on chromebooks) and 10-ish dead keys after about 2 yrs of daily use. The keyboards on these things just can't take my typing.

[staskhudzik]

If I were you, I would try re-installing alsa sound but given there appears to be an underlying issue with sound on Chromebooks it may not fix your issue - still worth a try now that it is all broken anyway!

You know, the funny thing is that de-installing and re-installing alsa-utils did not work, as alsa force-reload and replacing asound.state, BUT alsa force-unload did actually help restore alsamixer parameters and I was able to return the output sound. However, I still can't understand which parameter in alsamixer is responsible for mic sound and now I know that attempting at straight up unmuting everything risks messing the whole sound configuration.

[gdesilva]

Have you tried https://alsa.opensrc.org/ ?

EDIT : Check out this post https://bbs.archlinux.org/viewtopic.php?id=252123 - read the second and the last post by uhmzilighase. The problem is not identical to yours but it is claimed that only certain versions of alsa packages work on Braswell.