On Sat, 15.09.07 09:59, Konstantin Ryabitsev (icon@fedoraproject.org) wrote:
Hi!
Since there isn't a mic input jack on Mac Mini, I have to use a USB headset. If I leave it plugged in when booting, the HDA Intel onboard device doesn't even show up any more in my ALSA device selector -- only USB audio devices are present. So, I have to remember to unplug the headset before booting, in order for the onboard audio to still show up and work (we like music).
I don't think this is desired behaviour -- both devices appear to work correctly when I plug in the USB headset after the boot.
I'm not sure if this is the same as https://bugzilla.redhat.com/show_bug.cgi?id=219023, but the symptoms do seem similar.
Can anyone confirm with other devices? This is on F7.
This is probably caused by /etc/modprobe.conf fragments that system-config-sound writes. Those fragments are written to make the binding between audio device and ALSA device index stabl. However, they cause problems when an audio device is later plugged in that was not plugged when s-c-s was first run.
So, as far as I understood the problem: s-c-s finds your first sound card, decides it should get index 0 assigned. Hence it writes a fragment which enforces this mapping. Now, on next bootup a new device is around, which is configured by the kernel before the already known one. Because it has no modprobe.conf fragment it gets an index assigned automatically. The first one that is free happens to be 0, so it get's that index assigned. Next the already known sound card gets configured by the kernel. The modprobe.conf fragment is used, which assigns it index 0 -- which however is already taken at this point. And thus the "main" device is not configured and thus doesn't appear anymore.
So, what's the fix for this?
A quick fix would be to simply remove that modprobe.conf fragment in question.
For Fedora the right fix is probably to remove s-c-s from firstboot, so that the fragment is not written anymore. It's obsolete now, anyway.
Of course, that way we lose the fixed alsa device indexes. But, in -- my opinion -- that was a bad idea anyway. Sound cards should be identified by a device path, like the HAL device string. PulseAudio always uses HAL device strings for identification of sound cards. Since we moved to PA now, this problem thus goes away.
This all is an educated guess. Haven't checked if the above recommendations actually fix your problem. Please report back!
Lennart