[pulseaudio-discuss] Order-based or priority-based default device?

[David Henningsson]

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 
hibernate.

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.
http://launchpad.net/~diwic