7 Mar
2022
7 Mar
'22
9:55 a.m.
On Mon, Mar 07, 2022 at 11:21:59AM +0900, Oh Eomji wrote:
In mobile, a co-processor can be used with USB audio to improve power consumption. To support this type of hardware, hooks need to be added to the USB audio subsystem to be able to call into the hardware when needed.
The main operation of the call-backs are:
- Initialize the co-processor by transmitting data when initializing.
- Change the co-processor setting value through the interface function.
- Configure sampling rate
- pcm open/close
- other housekeeping
Known issues:
- This only supports one set of callback hooks, meaning that this only works if there is one type of USB controller in the system. This should be changed to be a per-host-controller interface instead of one global set of callbacks.
Also, this is a non-starter, and not going to work at all, sorry. Most devices have more than one USB controller in the system, and we can never accept changes that break that model.
Nor would you want us to, as it would break many Samsung devices...
thanks,
greg k-h