Cannot start JACK under Plasma

I need to be able to use JACK in near future, already tried to configure it myself, despite being in groups, raising rtprio to 90 and memlock to unlimited, and also sometimes killing pulse beforehand, I get the same errors, when trying to start JACK using different methods:

jackd -dalsa -dhw:0 -r48000 -p1024 -n2:
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
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
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
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

Cadence:

Tue Apr 28 09:06:49 2020: setting parameter 'engine':'driver':'(null)' to value "alsa"
Tue Apr 28 09:06:49 2020: setting parameter 'engine':'realtime':'(null)' to value "true"
Tue Apr 28 09:06:49 2020: setting parameter 'engine':'verbose':'(null)' to value "false"
Tue Apr 28 09:06:49 2020: setting parameter 'engine':'sync':'(null)' to value "false"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'device' to value "hw:Generic"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'playback' to value "hw:Generic"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'rate' to value "48000"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'period' to value "1024"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'nperiods' to value "2"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'hwmon' to value "true"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'hwmeter' to value "false"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'softmode' to value "false"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'monitor' to value "false"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'dither' to value "n"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'shorts' to value "false"
Tue Apr 28 09:06:49 2020: setting parameter 'drivers':'alsa':'midi-driver' to value "seq"
Tue Apr 28 09:06:49 2020: Listening for D-Bus messages
Tue Apr 28 09:06:56 2020: Starting jack server...
Tue Apr 28 09:06:56 2020: JACK server starting in realtime mode with priority 10
Tue Apr 28 09:06:56 2020: self-connect-mode is "Don't restrict self connect requests"
Tue Apr 28 09:06:56 2020: Acquired audio card Audio0
Tue Apr 28 09:06:56 2020: creating alsa driver ... hw:Generic|-|1024|2|48000|0|0|hwmon|swmeter|-|32bit
Tue Apr 28 09:06:56 2020: ERROR: ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to capture-only mode
Tue Apr 28 09:06:56 2020: Released audio card Audio0
Tue Apr 28 09:06:56 2020: ERROR: Cannot initialize driver
Tue Apr 28 09:06:56 2020: ERROR: JackServer::Open failed with -1
Tue Apr 28 09:06:56 2020: ERROR: Failed to open server

Qjackctl:

09:08:05.888 Statistics reset.
09:08:05.990 ALSA connection change.
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
09:08:06.651 ALSA connection graph change.
09:08:18.585 JACK is starting...
09:08:18.586 /usr/bin/pasuspender -- jackd -dalsa -dhw:Generic -r48000 -p1024 -n2 -Xseq -P
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
09:08:18.613 JACK was started with PID=20749.
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"
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:Generic|-|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
09:08:18.771 JACK was stopped
09:08:20.815 Could not connect to JACK server as client. - Overall operation failed. - Unable to connect to server. Please check the messages window for more info.
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

Am I missing something obvious?

hi @mardab, i would try following this tutorial.

Will do, thanks for quick response. What should I do in case that won't work?

Did you manage to set it up successfully?

almost - there are no working inputs under JACK, apart from ability to make a feedback loop

Have you used realtimeconfigquickscan script to check if system is configured correctly for realtime audio?

ERROR: ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to capture-only mode

please get ALSA information

 sudo alsa-info.sh --upload

and post link to data uploaded to alsa-project

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