Re: [LAU] How to recover from a JACK freeze? - Linux-audio-user

19 Aug 2017

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 From: James Harkins &lt;jamshark70(a)zoho.com&gt;
 To: "linux-audio-user" &lt;linux-audio-user(a)lists.linuxaudio.org&gt;
 Subject: [LAU] How to recover from a JACK freeze?
 Message-ID: &lt;15df368d100.cbae553a56821.8435360232489998174(a)zoho.com&gt;
 Content-Type: text/plain; charset="UTF-8"

 Hi, been inactive for a while.

 I just up/cross-graded to Ubuntu Studio 16.04 -- very much enjoying it so
 far! I'm getting better USB audio performance than I could ever manage
 under plain Ubuntu (provided WiFi is off, but I can live with that for
 shows).

 One problem that the upgrade didn't solve is that sometimes jackd gets
 stuck and it can't be killed.

 Initial symptom: No audio, in or out.

 Secondary symptom: In qjackctl, the CPU usage number is frozen -- never
 changes.

 At that point:

 $ ps x | grep jackd
  3140 ?        SLsl   0:16 /usr/bin/jackd -dalsa -r44100 -p1024 -n2 -D
 -Chw:Set,0 -Phw:Set
  4458 pts/1    S+     0:00 grep --color=auto jackd
 $ kill -9 3140
 $ ps x | grep jackd
  3140 ?        SLsl   0:16 /usr/bin/jackd -dalsa -r44100 -p1024 -n2 -D
 -Chw:Set,0 -Phw:Set
  4460 pts/1    S+     0:00 grep --color=auto jackd

 "kill -9" has no effect.

 "sudo kill -9" has no effect.

 If I reboot, it takes several minutes for the system to shut down -- i.e.,
 jackd is even preventing a clean shutdown.

 So, the question: How do I regain control when this happens? (Ideally,
 without having to close everything.)

Pretty sure I've seen the same thing a few times, and the solution has been
to reload the sound card driver. Here's my script to do that:

[kjetil@localhost ~]$ more bin/startdelta.sh
#!/bin/sh

fuser -fv /dev/snd/* /dev/dsp*

/home/kjetil/bin/removealsa.sh # see below
sleep 1
/home/kjetil/bin/alsasound start # ccrma dist script

modprobe snd-ice1712 # change to your sound card
#modprobe snd-hda-intel
modprobe snd-seq
chmod 777 /dev/snd/seq

alsactl restore 0

fuser -fv /dev/snd/* /dev/dsp*

[kjetil@localhost ~]$ more bin/removealsa.sh
#!/bin/sh
killall -9 pulseaudio
rmmod snd_hda_codec_atihdmi snd_hda_codec snd_hwdep snd_pcm snd_timer snd
soundcore snd_page_alloc
rmmod snd_seq snd_timer snd_seq_device snd_seq_dummy snd-ice1712
snd_ice17xx_ak4xxx snd_ak4xxx_adda snd_hda_intel snd_cs8427 snd_hda_codec
snd_ac97_codec snd_hwdep snd_seq snd_pcm ac97_bus snd_i2c snd_mpu401_uart
snd_rawmidi snd_seq_device snd_timer snd soundcore snd_page_alloc
sleep 1
rmmod snd_hda_codec_atihdmi snd_hda_codec snd_hwdep snd_pcm snd_timer snd
soundcore snd_page_alloc
rmmod snd_seq snd_timer snd_seq_device snd_seq_dummy snd-ice1712
snd_ice17xx_ak4xxx snd_ak4xxx_adda snd_hda_intel snd_cs8427 snd_hda_codec
snd_ac97_codec snd_hwdep snd_seq snd_pcm ac97_bus snd_i2c snd_mpu401_uart
snd_rawmidi snd_seq_device snd_timer snd soundcore snd_page_alloc

rmmod
snd_seq_midi,snd_seq_dummy,snd_ice1712,snd_ak4xxx_adda,snd_cs8427,snd_ac97_codec,snd_seq,snd_pcm,snd_timer,snd_i2c,snd_mpu401_uart,snd_rawmidi,snd_seq_device

rmmod snd_seq_midi,snd_seq,snd_timer,snd_rawmidi,snd_seq_device

rmmod snd_seq_midi_event snd-seq-midi snd-seq snd-timer snd-rawmidi
snd-seq-device

rmmod snd_seq_oss snd_seq_midi_event snd_pcm_oss snd_seq snd_seq_device
snd_pcm snd_timer snd_page_alloc snd_mixer_oss

rmmod snd_hda_codec_realtek snd_hda_codec_via snd_hda_codec snd_hwdep
snd_pcm snd_timer
rmmod snd_hda_codec snd_hwdep snd_pcm snd_timer
rmmod snd_via82xx snd_hda_codec snd_hwdep snd_ac97_codec snd_mpu401_uart
snd_rawmidi snd_seq_device snd_pcm snd_timer snd_page_alloc soundcore

rmmod snd