pulling an external soundcard out from under ALSA hangs mixxx

[Nick]

I got an external soundcard and told Mixxx to use it for headphone cueing. Then I pulled the soundcard and Mixxx kept playing. Then I went into the prefs and saw that the soundcard was still listed there. I clicked "Ok" and the UI froze and mixxx got stuck in a loop of this:

Expression 'AlsaStop( stream, 0 )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2373
Expression 'AlsaRestart( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2415
Expression 'PaAlsaStream_HandleXrun( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2952
Expression 'snd_pcm_drop( stream->playback.pcm )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2181
Expression 'AlsaStop( stream, 0 )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2373
Expression 'AlsaRestart( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2415
Expression 'PaAlsaStream_HandleXrun( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2952
Expression 'snd_pcm_drop( stream->playback.pcm )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2181
Expression 'AlsaStop( stream, 0 )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2373
Expression 'AlsaRestart( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2415
Expression 'PaAlsaStream_HandleXrun( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2952
Expression 'snd_pcm_drop( stream->playback.pcm )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2181
Expression 'AlsaStop( stream, 0 )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2373
Expression 'AlsaRestart( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2415
Expression 'PaAlsaStream_HandleXrun( self )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2952

[RJ Skerry-Ryan (rryan)]

Probably still an issue. Can somebody test?

[Sean M. Pappalardo (pegasus-renegadetech)]

As of trunk r2648, it's much improved. While the console shows the same messages, it only does so once, but the output still just stutters. The GUI remains responsive however and if you go into the sound prefs and hit Query Devices, the output goes quiet and all selected devices change to "None." If you then select one and click OK, Mixxx resumes playback.

So ideally, we'd need to somehow auto-detect a missing sound device and on detection, automatically re-query devices, selecting "None" for the now-missing one and leaving the others as they were.

[Sean M. Pappalardo (pegasus-renegadetech)]

Update: what I said above applies when the removed device is the master output. If it's the headphone one, the master one continues playing! Still, we should detect and recover from unplugged devices otherwise the prefs pane is no longer accurate.

[Sean M. Pappalardo (pegasus-renegadetech)]

I'm marking this Fix Committed since Mixxx no longer hangs when you remove an external sound card on-the-fly. It could more gracefully handle the situation, but that's another, much-lower-priority bug.

[RAWRR (rawrr)]

Re-validated in the newest windows version.

[RAWRR (rawrr)]

The night before last at the end of my set while the last song was playing I pulled my external headphone soundcard to put it away and Mixxx totally hung, just stopped. It started again when I plugged it back in. I was using 1.11 beta2 pre 3314 build and the ASIO driver.

This bug still exists.

[tomtom (thomas-8)]

Bug exists also on last 1.11-pre (20.03.2013) Tested with USB-Microphone on Linux Mint.

[Jonathan Bastnagel (jonthebagel)]

I've also had this issue, however, it seems to occur when I'm assigning Inputs for the Digital Vinyl Control.

[Tuukka Pasanen (pasanen-tuukka)]

Can this be ALSA-Pulseaudio-Portaudio brigde thing?

[Sean M. Pappalardo (pegasus-renegadetech)]

We're going to need developer confirmation before we mark this fixed.

[Sean M. Pappalardo (pegasus-renegadetech)]

On what OS did you test and with which sound card, @danger zack?

[Daniel Schürmann (daschuer)]

The Portaudio issue is tracked here:
https://app.assembla.com/spaces/portaudio/tickets/11/details?comment=1045708553#

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/5146