The silent stream is enabled with a Kconfig option, as well as a kernel
parameter should there be a need to override the build time default.
I'm not sure whether the module option is the best interface.
An alternative is a mixer element that controls dynamically. Then
it'll be per card unlike the module option.
+1, kcontrol seems the appropriate way to control this.
It was my suggestion to use Kconfig+kernel parameter for
simplicity/overrides.
The kcontrol is a nice idea, but in practice we typically only have one
card dealing with HDMI. It also doesn't have a UCM representation so
would force the use of amixer and manual configs, or the UCM file would
always set the mode.
