[pulseaudio-discuss] No startup detection with module-udev-detect in PulseAudio 0.9.18

Lennart Poettering lennart at poettering.net
Fri Oct 2 00:57:46 PDT 2009

On Fri, 02.10.09 03:58, Matthew W. S. Bell (matthew at bells23.org.uk) wrote:

> Hi,
> I recently upgraded to PulseAudio 0.9.18 on a Debian testing/unstable
> mix. On starting pulseaudio, no ALSA cards were detected by pulseaudio,
> though there are two present. With debug level information being output,
> pulseaudio stated only:
> I: module-udev-detect.c: Found 0 cards.
> I have talked to a couple of other people who seem to be having this
> problem.
> Using printf debugging, I found that processing was at least reaching
> module-udev-detect.c:process_device for each card, which makes me
> suspect the udev_device_get_action() logic, as I believe, on startup,
> the devices will not have an associated action.

The logic behind the actions for sound card devices is a bit
weird. Have you seen the comments at the top of

If those rules are not installed then things will not work. Which is
one of the reasons we require a brand new udev in PA. Last time I
checked Debian didn't have udev 143. Does it have that now? If it
doesn't then it is not exactly surprising if things don't work for

Also, for some weird reason Marco modifies the default udev rules
heavily. Which is really something he shouldn't do.
> To test this, I ran 'udevadm trigger', which resulted in both cards
> being detected. However, I now cannot reproduce the original problem.

This only triggers "change" events, which is what PA looks for. Try
triggering "add" events.


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

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