On 30/07/18 14:13, Takashi Iwai wrote:
On Mon, 30 Jul 2018 11:23:36 +0200, Jorge Sanjuan wrote:
Make use of UAC3 Power Domains associated to an Audio Streaming path within the PCM's logic. This means, when there is no audio being transferred (pcm is closed), the host will set the Power Domain associated to that substream to state D1. When audio is being transferred (from hw_params onwards), the Power Domain will be set to D0 state.
This is the way the host lets the device know which Terminal is going to be actively used and it is for the device to manage its own internal resources on that UAC3 Power Domain.
Note the resume method now sets the Power Domain to D1 state as resuming the device doesn't mean audio streaming will occur.
I guess we need the power state transition to D0 also in prepare callback. The recovery from suspend doesn't need hw_params call but just prepare -> trigger.
Right! Shouldn't it then be enough to just go to D0 on .prepare? I,e. Move the state transition from .hw_params to .prepare.
Jorge
One could think of implementing into the trigger, but since the transition needs some delay, prepare callback would be a better choice, as it seems.
thanks,
Takashi