Arch Linux

ericc8t

Member

Registered: 2020-05-02

Posts: 3

[Pulseaudio] Bug when removing remapped USB device

Hello,

First, I'm new to this community, having just switched to Arch since I believe it's the right choice to learn (an I have a lot to learn!) and to have the exact configuration I like to have.

Second, the encountered problem.

I'm trying to use my desktop speakers acting as a front-center channel when using my screen for movies (don't have TV, but a 32" monitor is enough!), complementing the 2 loudspeaker on the left and right sides of the desk. In short, a 3.0 configuration to have better clarity for the voices.
The desktop speakers are connected through USB: let's call the related sink usb_sink.

1) I remap the desktop channels as dual center speakers using
   

pacmd load-module module-remap-sink sink_name=virtual_center master=usb_sink channels=2 channel_map=center,center master_channel_map=left,right remix=no

   If I remove/turn off the USB speakers, the remapped sink remains, which is a bug I think, but it seems to be harmless so far.

2) But... Going further, I combine this virtual center with the front speakers (3.0 set-up) using
   

pacmd load-module module-combine-sink sink_name=hc1 slaves=front_sink,virtual_center channels=4 channel_map=left,right,center,center

   Now, if the USB speakers are deconnected, pulseaudio looses track and applications/volume control etc can no longer connect to it. Also, even though everything (well, except udev rules for sure) has been done as a normal user, pulseaudio is also crashed for other users.

  Even if I issue

pulseaudio -k
pulseaudio --start

a tool like pavucontrol shows "Establishing a connection to PulseAudio. Please wait..."
My solution so far is to reboot (there's for sure a better workaround).

I tend to see this as a bug, and I've started to read a few about udev, but it's also a pulseaudio problem and it's getting quite complex for me... so I'm asking!

Side question: when issuing commands like

pacmd load-module ...

I have no information when it fails. Just that

pacmd list-modules

shows that the module hasn't started correctly. How can I get error messages when using those commands?

Thanks!

Last edited by ericc8t (2020-05-03 07:22:29)

ericc8t

Member

Registered: 2020-05-02

Posts: 3

Re: [Pulseaudio] Bug when removing remapped USB device

Just found a solution to restart Pulseaudio:

systemctl --user restart pulseaudio.socket

takes a long time (more than 1 minute) but eventually works.

The bug remains though!

Last edited by ericc8t (2020-05-03 07:38:06)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,627

Re: [Pulseaudio] Bug when removing remapped USB device

You should probably report that upstream, afaik pulse will generally not automatically remove/discard explicitly defined sinks like that, even if the underlying physical HW sink got removed. One thing you might want to try is run pulseaudio in verbose mode (-vvvvv) to check whether the log gives any information on what it's doing.

Last edited by V1del (2020-05-03 10:40:32)

ericc8t

Member

Registered: 2020-05-02

Posts: 3

Re: [Pulseaudio] Bug when removing remapped USB device

OK, thanks, will do this!

Edit: https://gitlab.freedesktop.org/pulseaud … issues/878

Last edited by ericc8t (2020-05-03 17:56:54)