Comment 231 for bug 274995
Revision history for this message
| Dovel (dov01) wrote Re: MASTER storing ALSA mixer element values during shutdown hangs nondeterministically if non-loopback network interfaces are still up | #231 |
Just a note on the upgraded installation Intrepid 1 above, I do a fresh install each 2-3 releases of Ubuntu, so either Gutsy or Hardy would have been a fresh install from CD. Both of those systems had IPV6 enabled didn't they? While the bug is quite likely with alsa/pulseaudio, it is brought to our attention by network configurations.
Now it seems from my reading (and correct me if I am wrong) that ALSA operates on the current machine/filesystem only, whereas pulseaudio is a sound server, which extends the sounds capabilities of the system by making it possible or easier to serve sound across networks, between applications etc. Sort of like X for audio. So if our problem is anywhere it is either with pulseaudio or network configuration or even the relationship between ALSA and Pulseaudio.
1) Is there an easy way to remove pulseaudio from the equation, ie an isolation test, so we only have ALSA and the network running and have ALSA unaware of or logged in with pulseaudio?
We know that if we remove the computer from the network, our problem at shutdown disappears. I don't think ALSA really has anything to do with the network, except through Pulseaudio.
I propose an isolation test (running an affected system without pulseaudio being loaded) on a few different systems to verify Pulseaudio as a likely cause of the bug instead of ALSA alone.
2) I will also be checking for network config changes that could affect this issue between Hardy-Intrepid. Long shot, but could turn something up. Pulseaudio wasn't included in Gutsy and we haven't heard of this issue in Hardy, which did have Pulseaudio.
3) Another line of inquiry is to explore the relationship between ALSA and Pulseaudio. Does anyone know how it works and if this could be the root of the issue? Could it be that ALSA is still trying to poll for Pulseaudio on any available hosts or networks (eg. localhost)? Perhaps that is why the addition of localhost to the /etc/hosts file works. ALSA can see that Pulseaudio isn't there locally and stops looking. I could be wrong with this. I don't know how the relationship between them works.
These 3 areas would seem to me to be the 3 only likely causes of the bug.
Please feel free to tell me I'm wrong.
dov