[alsa-devel] Device creation order

Lennart Poettering mznyfn at 0pointer.de
Fri Apr 3 13:58:26 CEST 2009

On Fri, 03.04.09 09:50, Jaroslav Kysela (perex at perex.cz) wrote:

> >> - dynamic device creation at runtime - for example we have an
> >>    experimental HDA driver configuration code which might change
> >>    the arrangement of PCM devices on request from the user space
> >>
> >> I would suggest to wait awhile with some small timeout (0.5 sec?) for all
> >> devices to get the usual static arrangement working and handle extra
> >> dynamic cases, too.
> >
> > The current implementation of the ALSA framework guarantees that the
> > control device file is that latest one to be created for all the devices
> > created at initialization.  Any devices created later depend on some
> > userspace action, so a small timeout won't help in this case.
> The timeout might help to let alsactl utility to initialize the 
> soundcard's mixer. But I agree that alsactl should send a HAL message that 
> initial setting was done instead.

This is not an issue AFAICS. udev will run alsactl and only *after* that
finished forward the device creation events to HAL and then PA.


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

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