I have two computers and they have pretty similar manjaro installations. Both have the same jack2, QJackCtl and kernel versions installed.
Computer 1
This is the one that works:
I can start jack and hear stuff in lmms and Hydrogen. Other audio output from pulseaudio will then stop which is expected afaik. When stopping and starting jack in QJackCtl on this one, it looks like this:
01:01:48.817 Client deactivated. 01:01:48.827 JACK is stopping... Jack main caught signal 15 Released audio card Audio0 audio_reservation_finish 01:01:49.074 JACK was stopped 01:01:51.610 JACK is starting... 01:01:51.611 /usr/bin/jackd -dalsa -dhw:0 -r48000 -p1024 -n2 Cannot connect to server socket err = No such file or directory Cannot connect to server request channel jack server is not running or cannot be started JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock 01:01:51.652 JACK was started with PID=1969. Cannot create RT messagebuffer thread: Operation not permitted (1) Retrying messagebuffer thread without RT scheduling Messagebuffer not realtime; consider enabling RT scheduling for user no message buffer overruns Cannot create RT messagebuffer thread: Operation not permitted (1) Retrying messagebuffer thread without RT scheduling Messagebuffer not realtime; consider enabling RT scheduling for user no message buffer overruns Cannot create RT messagebuffer thread: Operation not permitted (1) Retrying messagebuffer thread without RT scheduling Messagebuffer not realtime; consider enabling RT scheduling for user no message buffer overruns jackdmp 1.9.14 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2016 Grame. Copyright 2016-2019 Filipe Coelho. jackdmp comes with ABSOLUTELY NO WARRANTY This is free software, and you are welcome to redistribute it under certain conditions; see the file COPYING for details JACK server starting in realtime mode with priority 10 self-connect-mode is "Don't restrict self connect requests" Cannot lock down 82280346 byte memory area (Cannot allocate memory) audio_reservation_init Acquire audio card Audio0 creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods ALSA: final selected sample format for capture: 32bit integer little-endian ALSA: use 2 periods for capture ALSA: final selected sample format for playback: 32bit integer little-endian ALSA: use 2 periods for playback Cannot use real-time scheduling (RR/10) (1: Operation not permitted) AcquireSelfRealTime error 01:01:53.832 JACK connection change. 01:01:53.834 Server configuration saved to "/home/mango/.jackdrc". 01:01:53.835 Statistics reset. 01:01:53.866 Client activated. 01:01:53.867 Patchbay deactivated. 01:01:53.882 JACK connection graph change. Cannot lock down 82280346 byte memory area (Cannot allocate memory) Computer 2
On this one, all pulseaudio apps will keep playing sound, lmms and Hydrogen won't. When stopping and starting jack in QJackCtl, this is all I see:
00:52:35.422 Client deactivated. 00:52:36.599 JACK connection change. 00:52:36.618 Client activated. 00:52:36.619 Patchbay deactivated. Cannot lock down 82280346 byte memory area (Cannot allocate memory) As you can see, it's not logging much stuff.
Inserting the /usr/bin/jackd -dalsa -dhw:0 -r48000 -p1024 -n2 command from the working machine here yields:
`default' server already active Failed to open server If I run the same command directly after a reboot or after using jack_control stop, it yields:
audio_reservation_init Acquire audio card Audio0 creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to capture-only mode Released audio card Audio0 audio_reservation_finish Cannot initialize driver JackServer::Open failed with -1 Failed to open server Same for jackd -d alsa
the PCM error message does not appear on computer 1.
On both machines, QJackCtl claims Jack to be "Active"
Where could I continue to look for the problem?
Thanks
jackd -d alsa -d hw:1makes sound play in lmms, but it sounds super glitchy and stuttering. pulseaudio is stopped when I run this.Setup...->Settings->Output Devicesetting this to ...(hw:1) does the same thing as using-d alsa -d hw:1. Audio still stuttering. The list of devices, and especially the numbering, corresponds to the output ofaplay -l("card 0", "card 1")realtime-privilegesand adding myself to the realtime group didn't change it.