[pulseaudio-discuss] alsa-util.c: Unable to attach to mixer
bignose+hates-spam at benfinney.id.au
Wed Jul 30 16:19:50 PDT 2008
Lennart Poettering <lennart at poettering.net> writes:
> On Sun, 27.07.08 14:42, Ben Finney (bignose+hates-spam at benfinney.id.au) wrote:
> > The trouble seems (to my eyes) to begin at the error message "ALSA lib
> > control.c:909:(snd_ctl_open_noupdate) Invalid CTL plug:hw:0".
> That message is not really important. PA tries to find the right mixer
> device for a PCM stream. ALSA has not real API for that. So we try a
> few things, which unfortuncately results in a bit of debug messages by
Okay, thanks for that reassurance.
> > $ sudo /usr/bin/pulseaudio -vvvv --daemonize=false
> -vvvvv? Better safe than sorry, heh?
I think I was told earlier that '-vvvv' would result in the highest
debugging level. What is the highest level of debugging that would be
useful in this case?
> > I: core-util.c: Successfully gained nice level -11.
> > W: main.c: This program is not intended to be run as root (unless
> > --system is specified).
> Don't run PA as root!
The daemon is to be started as a system service on startup, since no
users will be logging in; see earlier in the thread for why (summary:
this is a networked host with the desired audio devices, which is one
reason PulseAudio is attractive).
> > I: module-alsa-sink.c: Successfully opened device plug:hw:0.
> > I: module-alsa-sink.c: Successfully enabled mmap() mode.
> So you opened plug:hw:0 here.
> > ALSA lib control.c:909:(snd_ctl_open_noupdate) Invalid CTL plug:hw:0
> > I: alsa-util.c: Unable to attach to mixer plug:hw:0: No such file or directory
Is this not indicative that PA is still having trouble connecting to
> > I: alsa-util.c: Unable to attach to mixer hw:(null): No such device
> > I: sink.c: Created sink 0 "output" with sample spec "s16be 2ch 44100Hz"
> > I: source.c: Created source 0 "output.monitor" with sample spec "s16be 2ch 44100Hz"
> > I: module-alsa-sink.c: Using 4 fragments of size 4408 bytes.
> > D: module-alsa-sink.c: Thread starting up
> > D: rtpoll.c: Acquired POSIX realtime signal SIGRTMIN+29
> > I: module-alsa-sink.c: Starting playback.
> > I: module.c: Loaded "module-alsa-sink" (index: #0; argument: "device=plug:hw:0 sink_name=output").
This indicates PA thinks it *can* talk to 'plug:hw:0'. Which
interpretation is right?
> > D: cli-command.c: Checking for existance of '/usr/lib/pulse-0.9/modules/module-hal-detect.so': success
> > I: module-hal-detect.c: Trying capability alsa
> > D: module-hal-detect.c: Not loaded device /org/freedesktop/Hal/devices/computer_alsa_timer
> > D: module-hal-detect.c: Loading module-alsa-sink with arguments 'device_id=0 sink_name=alsa_output.pci_106b_3e_alsa_playback_0'
> > D: alsa-util.c: Trying front:0...
> And now you are trying to load another module for audio device 0?
I see nothing in my configuration (posted in the message to which you
replied) that requests a device '0'. Where would such a request come
> You shouldn't have both hal-detect and module-alsa-sink in your
> startup script. That usually makes no sense, unless you really know
> what you are doing.
Notice that the configuration has those two in an if-else relationship:
Since the output shows 'module-hal-detect.so' exists, this should mean
the 'load-module module-detect' will not occur. Is that right?
> > At that point the daemon is running, accepts connections, but
> > produces no sound. Eventualy I send it SIGINT and it closes.
> Have you set all volume sliders correctly and unmuted all controls?
Sound output works fine via ALSA on the host.
> "alsamixer -c0"? pavucontrol?
Both show the PCM output levels at 100%.
A PulseAudio client (a GNOME session, in this case) on another host
connects successfully, shows when the server is available or not, and
has its volume set to 100%.
The connection results in the following server output:
I: socket-server.c: TCP connection accepted by tcpwrap.
I: client.c: Created 0 "Native client (TCP/IP client from 127.0.0.1:52980)"
I: client.c: Client 0 changed name from "Native client (TCP/IP client from 127.0.0.1:52980)" to "PulseAudio Volume Control"
Testing the client (via GNOME's "Preferences -> Sound -> Devices ->
Music and Movies -> Test") cycles without anything audible, until I
> Are you sure your stream is connected to the right device?
How can I tell? What should I try to test this?
\ “Experience is that marvelous thing that enables you to |
`\ recognize a mistake when you make it again.” —Franklin P. Jones |
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