How to disable Dom0:mic?

User Support
1

Hi,

I recently installed Qubes, and saw that the usb icon on the top right, shows dom0:mic, and few more (webcam etc), I believe shutting down the sys-usb, should get rid of the webcam etc, but how do i disable the dom0:mic, I believe unless connected to a qube these will not be used, but I want to know if there is a good way to just keep them disabled completely

2

If we’re talking about preventing the accidental enablement of a microphone through it’s mute/unmute keyboard button, then I’d just click on the speaker icon on the panel, then open up the audio mixer from its menu, go to the Configuration tab and switch “Analog Stereo Duplex” to “Analog Stereo Output”.

If you’d like to use this option, and later on go back to having an enabled microphone, some weird stuff related to the keyboard hotkey handling the proper device might be present, e.g. muting/unmuting the microphone seems to do nothing - in this case what worked for me was switching to the “Input Devices” tab and setting the “Built-in Audio Analog Stereo” device as the fallback one (by clicking on the check mark button on its right).

Correct.

I’d just note that when disabling such a device, when it’s being used in a qube, may cause some unexpected things to happen, e.g. in the case of the microphone I noticed that the input stream got stuck at processing a loud noise, or in the case of an active webcam it might be, so that it’s diode stays lighten up, despite not using the webcam.

3

I am not completely sure how dom0:mic functions, but as far as I understand it, it is virtual and doesn’t do much unless a hardware microphone is present. Or if you are piping output to input to record it.

Answering your last question, the most reliable way to keep a device disabled is the hardware level. Either a power switch or physically disconnecting it from the system.

You also can try to disable them like this, but it only works if the driver has this functionality.

That said, sys-usb is there exactly for the purpose of allowing you to control USB devices in a compartmentalized and centralized way. Why shut it down?