Comment 59 for bug 394500

Revision history for this message
Peter Meiser (meiser79) wrote : Re: [Karmic] processes holding /dev/dsp* or /dev/snd/pcm* cause "pulseaudio: card not found - Null Output / Dummy Output"

Analyzing the issue, the problem lies in module-udev-detect. It checks for closed status on all PCM subdevices for the audio card:

line 185 of src/modules/module-udev-detect.c:
            if (!pa_streq(line, "closed\n")) {
                busy = TRUE;
                break;
            }

I added some pa_log_info to see the content:
D: module-udev-detect.c: /dev/snd/controlC0 is accessible: yes
I: module-udev-detect.c: card_path is: /proc/asound/card0
I: module-udev-detect.c: pcm_path is: /proc/asound/card0/pcm6c
I: module-udev-detect.c: sub_status is: /proc/asound/card0/pcm6c/sub0/status
I: module-udev-detect.c: line is: state: PREPARED
I: module-udev-detect.c: pcm_path is: /proc/asound/card0/pcm6p
I: module-udev-detect.c: sub_status is: /proc/asound/card0/pcm6p/sub0/status
I: module-udev-detect.c: line is: state: PREPARED
I: module-udev-detect.c: pcm_path is: /proc/asound/card0/pcm1p
I: module-udev-detect.c: sub_status is: /proc/asound/card0/pcm1p/sub0/status
I: module-udev-detect.c: line is: closed
I: module-udev-detect.c: pcm_path is: /proc/asound/card0/pcm0c
I: module-udev-detect.c: sub_status is: /proc/asound/card0/pcm0c/sub1/status
I: module-udev-detect.c: line is: closed
I: module-udev-detect.c: sub_status is: /proc/asound/card0/pcm0c/sub0/status
I: module-udev-detect.c: line is: closed
I: module-udev-detect.c: pcm_path is: /proc/asound/card0/pcm0p
I: module-udev-detect.c: sub_status is: /proc/asound/card0/pcm0p/sub0/status
I: module-udev-detect.c: line is: closed
D: module-udev-detect.c: /devices/pci0000:00/0000:00:1b.0/sound/card0 is busy: yes
I: module-udev-detect.c: Found 1 cards.

Now, the problem is that the modem is in "PREPARED" state all the time. Thus, module-udev-detect fails.