chtrt5645: crackling sound on background

plbossart / UCM

UCM files for Intel platforms

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chtrt5645: crackling sound on background #11

Closed stockmind closed 6 years ago

stockmind commented 7 years ago

Hi there,

I successfully installed your UCM driver for following device: chtrt5645 on a GPD Pocket mini-laptop. (Atom x7-8750 Cherry Trail, Realtek ALC5645, built-in stereo speaker, microphone, 3.5mm headset jack)

I'm using 4.12 kernel compiled from here https://github.com/jwrdegoede/linux-sunxi

Audio works but i can hear a noisy "crackling" sound on background. It sounds like the background noise of a bonfire. Weak but is there. On high volume i can hear it clearly. This doesn't happen on Windows.

There is something i could provide to help debugging? There is something i need to check?

Thank you!

plbossart commented 7 years ago

do you hear the noise on the headphone, speaker or both outputs? I do have noise on the headphone but things work fine with the speakers on my Asus T100 HA

stockmind commented 7 years ago

Speakers for sure, not sure about headphones. Will test it out shortly.

stockmind commented 7 years ago

Headphones doesn't work on 4.12 (some weak noises randomly but no audio), but works on 4.13. The crackling noise is on both on 4.13, speakers and headphones.

plbossart commented 7 years ago

this could be due to a bad set of ALSA controls or to a bad kernel-level configuration. You could try to play with alsamixer to try to see if you come up with some indications of better audio (be careful, this could blow your speakers so use low volume). If nothing works, it's likely the kernel configuration with things like voltages not well configured - you would need to open a bug on bugzilla.kernel.org and copy me and Bard Liao at Realtek

stockmind commented 7 years ago

Just tried to play around with volumes and some other setting, just randomly actions while listening to some music just to try to see if something changes. I'm not an expert and lot of the acronyms in mixer doesn't mean anything to me. Cannot get rid of the crackling noise, neither lower it. I've tried also muting almost everything and unmute one-by-one. I've tried the audio-test from Sound Settings in System Settings of Unity. Audio works only when pressing "Left" button. "Right" doesn't play any sound, don't know if it can help figure out the problem. Will check other bug related to audio driver and attach required files for debug. Thanks

plbossart commented 7 years ago

some platforms only have a mono speaker, that could explain your setup. You'd need to route the right data to the left (see example in the rt5640 case)

stockmind commented 7 years ago

It seems that the bug is already open: https://bugzilla.kernel.org/show_bug.cgi?id=196351 How can i add you and Bard Liao? thanks!

plbossart commented 7 years ago

i added Bard on the bugzilla, let's continue the discussion there.