[pulseaudio-discuss] Order-based or priority-based default device?
david.henningsson at canonical.com
Wed Sep 7 06:37:37 PDT 2011
The idea of "start to use what you plug in" is nice. If you plug
something in, you likely want to use it. Or do you? Anyway, that
approach seems to me to have an unsolvable problem: We don't know that
it actually was plugged in.
I've tried to talk to a few people, and from what I can tell, there is
no point in time when the system can be considered to be fully "up and
running". This means e g, if a new bluetooth device shows up say 30
seconds after PulseAudio starts, we don't know if this was because
someone actually connected the bluetooth headset at that point, or if it
was connected from start but took 30 seconds to respond and negotiate
with the bluez stack. Same goes for USB, and in theory other devices as
well, but I've never seen it happen in practice to anything internal/PCI.
Also, this applies not only at boot, but also at resume from suspend or
Given that lack of information from the kernel/hardware, I can only
assume that order-based handling is bound to fail. And so is
module-switch-on-connect, that implements this. (And so is Ubuntu's
suspend/resume script, btw.)
This leaves us rule/priority-based policy decisions, which I believe is
what Colin thinks as well. Comments?
David Henningsson, Canonical Ltd.
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