18:04 <alyssa> Odd issue -- I have headphones setup with RK3399/ChromeOS-kernel/etc.. They work, but whenever any sound is playing (or for a few seconds after), there is very discernible line noise in the background... Is the DAC just that low-cost? =P

18:05 <alyssa> I can reproduce on a different set of headphones as well.

18:12 <mmind00> alyssa: I guess eballetbo[m] might know?

18:13 <mmind00> alyssa: it also happens with the original chromeos kernel?

18:16 <alyssa> mmind00: It's not the "original" -- I compiled it from CrOS sources -- but it's certainly not mainline :)

18:18 <mmind00> alyssa: in that case dianders might know whom we could pester ... but I guess you don't have a pristine chromeos on your keving anymore though?

18:21 <alyssa> mmind00: Certainly not :P

18:21 <alyssa> An easy way to repro anyway is to play some audio over headphones routed through ALSA/Pulse, and then set the volume to zero, and then you're left with just the noise

18:21 <dianders> alyssa: Hrm, I never use wired headphones. Let me see if I can dig some up and try it. We could ask Dylan. The first thing I'd ask though is if you've tried running on battery vs AC and see it it matters.

18:22 <alyssa> I'm on battery now, let's find out

18:23 <alyssa> Audibly, no difference plugging into AC

18:24 <dianders> I don't seem to hear any hiss, but it's not super quiet in this room.

18:26 <dianders> You could try downloading an official recovery image and putting that on the device and see if you can reproduce?

18:27 <alyssa> It's entirely possible there's a userspace bug

18:27 <alyssa> (I am able to reproduce on my other Kevin, running mainline, no radios enabled)

18:28 <dianders> Also: you said you have a Chrome OS kernel, but I think userspace is pretty involved in getting audio setup properly. I know there's always a whole lot of audio config per board. Like: https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/refs/heads/master/overlay-kevin/chromeos-base/chromeos-bsp-kevin/files/audio-config/

18:28 <alyssa> Indeed.

18:29 <alyssa> I have some random files from that repo sprawled about the filesystem which is how I got headphones working at all; I'd believe I have it wrong

18:32 <alyssa> Specifically, I have the pair of files in ucm-config in that repo, and then a script doing:

18:32 <alyssa> ALSA_CONFIG_UCM=/opt/alsa/ucm alsaucm -c rk3399-gru-sound set _verb HiFi

18:32 <alyssa> amixer -c 0 sset 'Headphones' unmute

18:33 <alyssa> IIRC this is the procedure used in ALARM but I can't keep track of where I find these things anymore ;)

18:34 <dianders> alyssa: Sorry, all the audio stuff is totally over my head. Presumably the best thing to do would be to figure out how to get back to a known working state (like what official Chrome OS does assuming that works for you) and figure out how it's different...

18:35 <alyssa> dianders: "Audio stuff is totally over my head" I'm a graphics person, you think I have a clue what I'm doing either? ;D

18:39 <alyssa> I was hoping somebody might have seen this before. If not, that's alright; regardless, thank you for the suggestions! :)

18:47 <alyssa> Ooo, poking around alsamixer makes it worse! ...Wait

18:49 <anarsoul> alyssa: audio is way easier than gpu :)

19:21 <dianders> alyssa: possibly amstan might also know something about it?

19:28 <alyssa> anarsoul: Mayhaps :)

20:25 <amstan> alyssa: last time i tried this things just worked with the ucm, i'm sorry I didn't have anything to add

20:26 <amstan> alyssa: just be careful with this stuff, there's a chance you can end up with burnt speakers

20:26 <amstan> alyssa: leming might have had some experience with sound on gru too, he's the alarm maintainer

20:33 <vagrantc> /18/18

22:33 <alyssa> amstan: "Just worked" ...after you banged on it for 2 hours? ;)

22:33 <alyssa> Burnt speakers would be annoying, yes..