Op 12-4-2011 18:30, Sean McNamara schreef: > Hi, > > On Tue, Apr 12, 2011 at 12:15 PM, duportail<poort at telenet.be> wrote: >> Try to test the new xubuntu 11.04 with kde on a multi-user system. >> The first user (for example user1) can log in and gets a default sink from >> pulse. >> The second user(for example user2) that will log in gets a auto_null because >> pulse did not found any sinks. >> If i log out user1, than user2 can get a default sink by kill and start >> pulse. >> Where should be the reason? > This is the "classic" multi-user problem: you're using a soundcard > without hardware mixing, so only one ALSA application can take direct > control of the hardware device at a time. user1's pulseaudio daemon > takes control of it, so obviously user2's PA daemon will just get > "Device or resource busy" when trying to snd_pcm_open() on hw:0 (for > example). This problem has existed since ALSA existed. There's no > direct fix without scrapping the API and rewriting it. > > I guess there is no solution yet (still) in 11.04, but you can see > that folks in the Ubuntu community are trying to resolve the issue > with a number of possible approaches: > https://wiki.edubuntu.org/BluePrints/multiuser-soundcards-pulseaudio > > Running as system-wide is one possible approach... > http://www.pulseaudio.org/wiki/SystemWideInstance > > Not sure if there's yet a solution allowing the use of shm and > module-native-protocol-unix for multiple users (this is ideally what > you'd want for maximum performance / minimum latency), but it's quite > easy to set up module-native-protocol-tcp and connect to localhost > using the `default-server' parameter in client.conf, at the cost of > latency. Let me know if you need more details on this particular > approach. > > BTW, search the archives of this list at gmane< > http://blog.gmane.org/gmane.comp.audio.pulseaudio.general> -- there > are many many historical posts about multi-user setups. > > > > Sean > >> gd >> >> _______________________________________________ >> pulseaudio-discuss mailing list >> pulseaudio-discuss at mail.0pointer.de >> https://tango.0pointer.de/mailman/listinfo/pulseaudio-discuss >> > _______________________________________________ > pulseaudio-discuss mailing list > pulseaudio-discuss at mail.0pointer.de > https://tango.0pointer.de/mailman/listinfo/pulseaudio-discuss > Sorry, forgot to mention: there multiple (two) usb soundcards on the system.It is working good on xubuntu 10.10. As you said, the second user gets a "Device or resource busy".When I logout the first user, the second user can get a default sink. gd
