[Bug 1805079] Re: click/pop noise in the headphone on several lenovo laptops

I also have the quiet sound after the boot (but not too quiet).

About the noise you mentioned, I didn't hear that yet.

About the "Line Out Playback Volume" and "{Headphone,Speaker} Playback
Volume, without my patch, the Headphone and Speaker has its own
independent DAC, with my patch, they share one DAC, then the mixer name
is changed to "Line Out".

Could you generate 2 alsa-info.txt?

1) under the quiet sound condition, sudo echo 1 >
/sys/modules/snd_hda_codec/parameters/dump_coef; alsa-info.sh; then
upload the generated alsa-info.txt-quiet-headphone

2) after the sound change back to normal (quiet->not quiet), sudo echo 1
> /sys/modules/snd_hda_codec/parameters/dump_coef; alsa-info.sh; then
upload the generated alsa-info.txt-notquiet-headphone.

thanks.

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https://bugs.launchpad.net/bugs/1805079

Title:
click/pop noise in the headphone on several lenovo laptops

Status in linux package in Ubuntu:
Fix Committed

Bug description:
[Impact]
Lenovo told us that some linux uers reported headphone noise on Lenovo's
website. After investigating, we found those Lenovo laptop mdoels all
have the codec of alc285, and we can reproduce the noise problem too.

[Fix]
Don't use the DAC of headphone, let headphone share the DAC with speaker,
the noise disappears.

[Test Case]
After applying this patch, we tested on Lenovo P52, P72, X1 carbon and X1
Yoda2, no noise anymore

[Regression Potential]
Low. This patch only apply to several lenovo machines, and after applying
this patch, both speaker and headphone still work very well.

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