22 Mar
2013
22 Mar
'13
11:51 p.m.
I'm trying to run jackd from a script that is triggered by udev. But
when I try to do so jackd complains:
jackd 0.122.0
...
JACK is running in realtime mode, but you are not allowed to use
realtime scheduling.
...
But the user trying to run jackd (pi) is a member of the audio group.
The udev rule looks like this:
ATTRS{idVendor}=="0218", ATTRS{idProduct}=="0001",
ACTION=="change",
RUN+="/usr/bin/sudo -u pi -s /home/pi/bin/drumpad"
Is this maybe related to using sudo? I'd like to get this working, the
idea is that whenever I plug in my drumpad the udev rule and thus the
script gets executed. The script checks if jackd is already started and
then moves on starting up jalv with the drumkv1 plug-in. The script
itself works fine, it's just the udev part that got me puzzled.
Thanks!
Jeremy
6:49 a.m.
On Fri, 2013-03-22 at 23:51 +0100, Jeremy Jongepier wrote:
Is this maybe related to using sudo?
I noticed that when checking the user by $USER or $EUID, the result
often is wrong, but the output of $(id -u) until now always was correct,
so directly after the sudo I would add
echo $? > id.log
id -u >> id.log
to the script. The $? to check if sudo is working and id -u to check if
it really does switch the user, assumed the output of $? should be 0.
7:48 a.m.
On Sat, 2013-03-23 at 06:49 +0100, Ralf Mardorf wrote:
On Fri, 2013-03-22 at 23:51 +0100, Jeremy Jongepier
wrote:
Hm?
My idea isn't good.
[root@archlinux rocketmouse]# /usr/bin/sudo -u rocketmouse -s echo ":)"
:)
[root@archlinux rocketmouse]# echo $?
0
[root@archlinux rocketmouse]# id -u
0
Perhaps you should test it by adding an additional sudo
[root@archlinux rocketmouse]# /usr/bin/sudo -u rocketmouse -s id -u
1000
just to test if it really does work as expected.
Is this maybe related to using sudo?
I noticed that when checking the user by $USER or $EUID, the result
often is wrong, but the output of $(id -u) until now always was correct,
so directly after the sudo I would add
echo $? > id.log
id -u >> id.log
to the script. The $? to check if sudo is working and id -u to check if
it really does switch the user, assumed the output of $? should be 0.
10:48 a.m.
ASAP (maybe this weekend) I'll try to do something similar for Arch and
Ubuntu, but I've got completely no knowledge about udev.
11:29 a.m.
Perhaps this can do the job. I've got no time to try it now, since it
seems to be too complicated for me to do it on the quick.
"udevil - udevil "mounts and unmounts removable devices [snip] It can
also selectively automatically start applications or execute commands
after mounting [snip]" -
https://wiki.archlinux.org/index.php/Udev#Automounting_udisks_wrappers
11:38 a.m.
On Sat, 2013-03-23 at 11:29 +0100, Ralf Mardorf wrote:
Perhaps this can do the job. I've got no time to
try it now, since it
seems to be too complicated for me to do it on the quick.
"udevil - udevil "mounts and unmounts removable devices [snip] It can
also selectively automatically start applications or execute commands
after mounting [snip]" -
https://wiki.archlinux.org/index.php/Udev#Automounting_udisks_wrappers
Perhaps it doesn't auto-mount, sorry.
1:39 p.m.
On 03/23/2013 11:29 AM, Ralf Mardorf wrote:
Perhaps this can do the job. I've got no time to
try it now, since it
seems to be too complicated for me to do it on the quick.
"udevil - udevil "mounts and unmounts removable devices [snip] It can
also selectively automatically start applications or execute commands
after mounting [snip]" -
https://wiki.archlinux.org/index.php/Udev#Automounting_udisks_wrappers
An USB MIDI drumpad is not a removable device that can be mounted.
Jeremy
2:02 p.m.
On Sat, 2013-03-23 at 13:39 +0100, Jeremy Jongepier wrote:
On 03/23/2013 11:29 AM, Ralf Mardorf wrote:
An USB MIDI drumpad is not a removable device that can be mounted.
Yes, I'm still confused since "device" vs "block device", so I
sent a
request to Arch general.
To: General Discussion about Arch Linux
Subject: udev
Date: Sat, 23 Mar 2013 12:00:45 +0100
Hi,
before I start learning how to use udev, I've got some questions to
understand what program can do or not do what I want. I don't want to
know how to do it, if something is able to do what I want, I'll do
research and read myself, I just want to know if it's possible and by
what program it is possible, assumed it can be done.
"udevil - udevil "mounts and unmounts removable devices [snip] It can
also selectively automatically start applications or execute commands
after mounting [snip]" -
https://wiki.archlinux.org/index.php/Udev#Automounting_udisks_wrappers
IIUC it doesn't auto-mount? Not that important for me.
Since I needed to remove gvfs, because it wakes up sleeping external USB
drives, I want to have something else to mount block devices as easy as
possible.
Does this or something else also enable to execute a command, after an
USB MIDI device is connected? IOW can I use it to launch jackd after an
USB MIDI device is connected or is there another way to do this?
Somebody on LAU tries to do something similar, until now without
success,
http://lists.linuxaudio.org/pipermail/linux-audio-user/2013-March/091699.ht… .
Any hints are welcome.
Regards,
Ralf
2:18 p.m.
On 03/23/2013 02:02 PM, Ralf Mardorf wrote:
Yes, I'm still confused since "device"
vs "block device", so I sent a
request to Arch general.
To: General Discussion about Arch Linux
Subject: udev
Date: Sat, 23 Mar 2013 12:00:45 +0100
Ralf,
I'd appreciate it if you do not send me off-list mails.
Thanks,
Jeremy
4:30 p.m.
On Sat, March 23, 2013 5:39 am, Jeremy Jongepier wrote:
On 03/23/2013 11:29 AM, Ralf Mardorf wrote:
Whats the difference?
Auto mount -> device gets plugged in -> mount gets run as user
drumpad -> device gets plugged in -> script gets run as user
In both cases some binary gets run to deal with the USB device that was
plugged in.
--
Len Ovens
www.OvenWerks.net
Perhaps this can do the job. I've got no time
to try it now, since it
seems to be too complicated for me to do it on the quick.
"udevil - udevil "mounts and unmounts removable devices [snip] It can
also selectively automatically start applications or execute commands
after mounting [snip]" -
https://wiki.archlinux.org/index.php/Udev#Automounting_udisks_wrappers
An USB MIDI drumpad is not a removable device that can be mounted. 
2:42 p.m.
On 03/22/2013 11:51 PM, Jeremy Jongepier wrote:
I'm trying to run jackd from a script that is
triggered by udev. But when I try to do so jackd
complains:
jackd 0.122.0
...
JACK is running in realtime mode, but you are not allowed to use realtime scheduling.
...
Hi Jeremy,
I've had the same error message and issue trying to start an application using jack
form an init.d
script at boot time. It seems that start-stop-daemon does not impose PAM ("Pluggable
Authentication
Module") limits to the process it starts. Maybe you are facing a similar issue with
udev. My
solution was to autologin the user and then start the application.
Cheers
--
Raphaël.
But the user trying to run jackd (pi) is a member of
the audio group. The udev rule looks like this:
ATTRS{idVendor}=="0218", ATTRS{idProduct}=="0001",
ACTION=="change", RUN+="/usr/bin/sudo -u pi -s
/home/pi/bin/drumpad"
Is this maybe related to using sudo? I'd like to get this working, the idea is that
whenever I plug
in my drumpad the udev rule and thus the script gets executed. The script checks if jackd
is already
started and then moves on starting up jalv with the drumkv1 plug-in. The script itself
works fine,
it's just the udev part that got me puzzled.
Thanks!
Jeremy
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
--
Raphaël
4:43 p.m.
On Sat, March 23, 2013 6:42 am, Raphaël BOLLEN wrote:
On 03/22/2013 11:51 PM, Jeremy Jongepier wrote:
Which would not work here... but, maybe try changing
/etc/security/limits.d/audio.conf (or it's equiv) to be user specific
instead of group. Nope that whole file relies on PAM.
There is always the ugly way:
Have your udev module touch a file on plug in and rm it on unplug. Run a
user space loop that looks for that file and runs jack (if needed) and
connects whatever. File gone resets to look for file coming back.
--
Len Ovens
www.OvenWerks.net
I'm trying to run jackd from a script that is
triggered by udev. But
when I try to do so jackd
complains:
jackd 0.122.0
...
JACK is running in realtime mode, but you are not allowed to use
realtime scheduling.
...
Hi Jeremy,
I've had the same error message and issue trying to start an application
using jack form an init.d
script at boot time. It seems that start-stop-daemon does not impose PAM
("Pluggable Authentication
Module") limits to the process it starts. Maybe you are facing a similar
issue with udev. My
solution was to autologin the user and then start the application. 
5:05 p.m.
On Sat, 23 Mar 2013 08:43:20 -0700, Len Ovens wrote
Which would not work here... but, maybe try changing
/etc/security/limits.d/audio.conf (or it's equiv) to be user specific
instead of group. Nope that whole file relies on PAM.
There is always the ugly way:
Have your udev module touch a file on plug in and rm it on unplug.
Run a user space loop that looks for that file and runs jack (if
needed) and connects whatever. File gone resets to look for file
coming back.
But why so utterly complex? Just write a small script that will
be executed by udev:
#!/bin/bash
# give us more realtime
ulimit -r 95
# N.B.: you might want to also aquire higher memory
# and nice settings ...
# run command ...
sudo -u your_user your_command
As a test, use
sudo -u your_user /bin/bash -c "id && ulimit -a"
to see whether it works.
HTH Ralf Mattes
--
R. Mattes -
Hochschule fuer Musik Freiburg
rm(a)inm.mh-freiburg.de
24 Mar
24 Mar
2:08 p.m.
On 03/23/2013 05:05 PM, R. Mattes wrote:
But why so utterly complex? Just write a small script
that will
be executed by udev:
#!/bin/bash
# give us more realtime
ulimit -r 95
# N.B.: you might want to also aquire higher memory
# and nice settings ...
# run command ...
sudo -u your_user your_command
As a test, use
sudo -u your_user /bin/bash -c "id && ulimit -a"
to see whether it works.
HTH Ralf Mattes
Hello Ralf,
Using a wrapper script with 'ulimit -r 95' and then calling my user
script did the trick. Many thanks!
I find this a bit weird because this sets the ulimit for the user root
right? Does any process ran by sudo on its turn inherit this setting? So
sudo doesn't do something with the permissions of the user mentioned by
the -u option?
Anyway, I'm a happy camper now, whenever I plug in the drumpad into my
Raspberry Pi it starts jalv hosting drumkv1 and within a few seconds I
get sound and can start drumming. My kids already had a lot of fun
playing with the drumpad although my oldest son is somehwat more
interested in the RPi and all the cabling. He even pulled out the SD
card while his little sister was banging on the drumpad. Everything just
kept going. Linux still amazes me every so often.
Regards,
Jeremy
31 Mar
31 Mar
11:05 p.m.
On 03/22/2013 11:51 PM, Jeremy Jongepier wrote:
I'm trying to run jackd from a script that is
triggered by udev. But
when I try to do so jackd complains:
jackd 0.122.0
...
JACK is running in realtime mode, but you are not allowed to use
realtime scheduling.
...
But the user trying to run jackd (pi) is a member of the audio group.
The udev rule looks like this:
ATTRS{idVendor}=="0218", ATTRS{idProduct}=="0001",
ACTION=="change",
RUN+="/usr/bin/sudo -u pi -s /home/pi/bin/drumpad"
Is this maybe related to using sudo? I'd like to get this working, the
idea is that whenever I plug in my drumpad the udev rule and thus the
script gets executed. The script checks if jackd is already started and
then moves on starting up jalv with the drumkv1 plug-in. The script
itself works fine, it's just the udev part that got me puzzled.
Thanks!
Jeremy
The script works now except for one thing, the JACK connections do not
get set up when I boot with the drumpad attached. After having logged in
I still can't set up the connections because either jack_connect and
aj-snapshot complain that JACK is not running while it does run and it
runs as the user I'm logged in with.
This is the script I've fabricated:
https://raw.github.com/AutoStatic/scripts/rpi/rpi/drumpad
I've attached a JACK log of booting with the drumpad attached. JACK
starts successfully, so do all clients but the connections are not set
up. If I then log in and do a jack_lsp -c I get the following back:
pi@jj-rpi ~ $ jack_lsp -c
JACK server not running
Something similar happens when I boot without the drumpad attached and
attach the drumpad when booted. Then I have to wait a while before I can
make the connections (hence the sleep 10 command before calling
aj-snapshot). It'd be nice if I could check somehow if JACK is ready to
make connections.
Anyone any idea? Thanks in advance.
Jeremy
6 Apr
6 Apr
7:09 a.m.
@Jeremy
This kinda reminds me of what happens when I run a script from udev. the
rule is for a usb audio device. the script runs an amixer command to set
device name and volume level, then runs jack. if I then run qjackctl
manually it doesn't 'see' jack running. a quick look in qps showed that
jackd is running as root. been banging my head against the wall trying to
figure out how to run the script as my_user instead of root. not sure if
this is in the neighborhood of what you're experiencing.
udev rule:
SUBSYSTEM!="sound", GOTO="90_my_usbaudio_end"
ACTION!="add", GOTO="90_my_usbaudio_end"
DEVPATH=="/devices/pci0000:00/0000:00:1d.2/usb6/6-1/6-1:1.0/sound/card?",
ATTR{id}="UsbAudio", RUN+="/home/my_user/.Amixer/AmixerUsb.sh"
LABEL="90_my_usbaudio_end"
AmixerUsb.sh:
#!/bin/sh
/usr/bin/jackd -dalsa -d hw:3 -r44100 -p1024 -n2
amixer -c 3 -- sset Speaker 10%
tweed
--
View this message in context:
http://linux-audio.4202.n7.nabble.com/Trying-to-run-jackd-from-udev-tp83749…
Sent from the linux-audio-user mailing list archive at Nabble.com.
14 Apr
14 Apr
2:52 p.m.
On 04/06/2013 07:09 AM, tweed wrote:
@Jeremy
This kinda reminds me of what happens when I run a script from udev. the
rule is for a usb audio device. the script runs an amixer command to set
device name and volume level, then runs jack. if I then run qjackctl
manually it doesn't 'see' jack running. a quick look in qps showed that
jackd is running as root. been banging my head against the wall trying to
figure out how to run the script as my_user instead of root. not sure if
this is in the neighborhood of what you're experiencing.
udev rule:
SUBSYSTEM!="sound", GOTO="90_my_usbaudio_end"
ACTION!="add", GOTO="90_my_usbaudio_end"
DEVPATH=="/devices/pci0000:00/0000:00:1d.2/usb6/6-1/6-1:1.0/sound/card?",
ATTR{id}="UsbAudio", RUN+="/home/my_user/.Amixer/AmixerUsb.sh"
LABEL="90_my_usbaudio_end"
AmixerUsb.sh:
#!/bin/sh
/usr/bin/jackd -dalsa -d hw:3 -r44100 -p1024 -n2
amixer -c 3 -- sset Speaker 10%
tweed
Hello tweed,
I'm experiencing something different because the weird thing is that
JACK runs as my user. But I'm going to try setting up something else, I
can't find any solution anywhere regarding my issue. Also my SD card got
corrupted so had to start from scratch again.
Jeremy
4243
days inactive
4266
days old
linux-audio-user@lists.linuxaudio.org
19 comments
7 participants
participants (7)
-
David -
Jeremy Jongepier -
Len Ovens -
R. Mattes -
Ralf Mardorf -
Raphaël BOLLEN -
tweed