[pulseaudio-discuss] pulseaudio cannot recognise ALSA plughw

Lennart Poettering lennart at poettering.net
Sun Dec 7 22:27:30 PST 2008

On Mon, 08.12.08 00:30, kaworu fw (kaworufw at gmail.com) wrote:

> Hello,


> I have a problem in starting pulseaudio with my EMU-0404USB after a recent
> upgrade from Fedora9 to Fedora10.
> It seems that pulseaudio cannot set some hw parameters to my card as
> follows.  It fails to startup with default configuration which uses HAL so I
> override the default.pa config file to force a load of module-alsa-sink with
> plughw:0,0.  However it doesn't help.
> $ pulseaudio
> I: caps.c: Limited capabilities successfully to CAP_SYS_NICE.
> I: caps.c: Dropping root privileges.
> I: caps.c: Limited capabilities successfully to CAP_SYS_NICE.
> E: alsa-util.c: Failed to set hardware parameters on plughw:0,0: Operation
> not permitted
> E: module.c: Failed to load  module "module-alsa-sink" (argument:
> "device=plughw:0,0"): initialization failed.
> E: main.c: Module load failed.
> E: main.c: Failed to initialize daemon.
> However the same device (plughw:0,0) works fine when I use aplay.  Any
> clues?  Thanks!

Looks like an ALSA issue to me. The plughw module doe not seem to be
able to properly reformat the audio data as needed for PA. Please
report to the ALSA people. This is most likely due to some
mmap/non-mmap conversion bug in plughw or so. Try if things start to
work in PA if you pass mmap=0 to the alsa sink module.

Also, please note that under almost all circumstances passing
plughw:0,0 is wrong. You should not specify the subdevice. Use
plughw:0 instead.


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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