Guest audio loss following Windows host suspend

[arQon]

(Similar to, but distinct from, https://www.virtualbox.org/ticket/19267)

Background is here: ​https://forums.virtualbox.org/viewtopic.php?f=6&t=98365 but I'll put everything important in this ticket.

The bug only occurs on Windows hosts (W10 1909 tested) - Linux hosts are fine.

No amount of disabling/re-enabling Audio in the Manager will return the VM to a working state, but suspending the guest via its own mechanism and then resuming it generally effects recovery, so my (ignorant) gut feel is that something has changed in the timing or behavior VBox's handling of suspend/resume that's caused the audio pieces to not quite sync up (i.e. resumed before ready or etc).

I have some potentially-useful endpoints to reduce the bisection, in the 6.0 branch: LKG is 6.0.12, FKB is 6.0.22. (The bug is also in the 6.1 branch since at least 6.1.6, through to 6.1.10, but I don't have any working versions of 6.1 to provide the other end).

I've posted a VBox.log in the forums, which I can duplicate here (or recreate with 6.1.10 if you prefer) - I'm not sure what the preference is for attachments.

Cheers.

[arQon]

Disabling and re-enabling Audio Out in the mini-toolbar can also sometimes get things working again, but seems less successful on average than suspening and resuming the guest (albeit quicker and much less disruptive). There are occasions where neither aproach works (or at least not within any manageable number of retries). There are no error messages in the logs: e.g.

128:05:04.119523 Audio: Disabling output for driver 'DSoundAudio'
128:05:04.119591 Audio: Disabling output for driver 'Untitled'
128:05:04.119643 Audio: Disabling output for driver 'Untitled'
128:05:04.120149 Audio: Status has changed (input is disabled, output is disabled)
128:05:04.127028 GUI: UIMediumEnumerator: Medium-enumeration finished!
128:05:09.135281 Audio: Enabling output for driver 'DSoundAudio'
128:05:09.135347 Audio: Enabling output for driver 'Untitled'
128:05:09.135398 Audio: Enabling output for driver 'Untitled'
128:05:09.135909 Audio: Status has changed (input is disabled, output is enabled)
128:05:09.142406 GUI: UIMediumEnumerator: Medium-enumeration finished!

even on rounds that fail to work.

The guest is currently using the default AC97 controller. I'll try it with HDA next time I restart it. Again though, Linux hosts don't have this problem with the same guest, and nor do versions up to at least 6.0.12, so even if that works (or works more often, etc) I suspect it's likely to only do so by chance. Still, we'll see how it goes. :)

[arQon]

Disabling and re-enabling Audio Out in the mini-toolbar can also sometimes get things working again

On 6.1.16 (though I suspect by luck as much as anything else) this seems to at least work more often than not. It obviously has significant advantages over suspending and resuming the VM from a user perspective, and the clunkiness of the hack can be dealt with via a batch file:

VboxManage controlvm <vm> audioout off && VboxManage controlvm <vm> audioout on

Since doing this manually has been shown to not work fully reliably, this obviously won't either, but it's something.

What that actually means as far as resolving the bug goes is anybody's guess, but hopefully someone will find the time (or a support contract) needed to resolve it someday. :)

[RocketSLC]

Can confirm that I am also having this issue - Disabling and re-enabling audio out does temporarily fix it, but it always comes back.

[boxer01]

Currently solved as of #18594#comment:31

[arQon]

I'll test 6.1.18 when I get a chance: unfortunately the machine was downgraded to 6.1.14 just a few days ago because of the lockup bugs in .16, so it may be a couple of weeks before I can try the new rev. Thanks.

[arQon]

Still broken as of 6.1.18, unfortunately.