Re: [PATCH 5/6] audio/jack: honour the enable state of the audio device

[Gerd Hoffmann]

On Sat, Jun 13, 2020 at 02:05:17PM +1000, Geoffrey McRae wrote:
> When the guest closes the audio device we must start dropping input
> samples from JACK and zeroing the output buffer samples. Failure to do
> so causes sound artifacts during operations such as guest OS reboot, and
> causes a hang of the input pipeline breaking it until QEMU is restated.
> 
> Closing and reconnecting to JACK was tested during these enable/disable
> calls which works well for Linux guests, however Windows re-opens the
> audio hardware repeatedly even when doing simple tasks like playing a
> system sounds. As such it was decided it is better to feed silence to
> JACK while the device is disabled.

Hmm, I guess feeding silence into jack needs some cpu cycles?
Maybe add a timer to close the jack server connection?  Keep the
connection open for re-use for a while, but in case the guest stops
playing sound altogether close the jack connection after being unused
for a few minutes?

[ Doesn't render the patch invalid, consider it a suggestion for future
  improvements ]

take care,
  Gerd