On Tue, 20 Oct 2015, Vinod Koul vinod.koul@intel.com wrote:
On Tue, Oct 20, 2015 at 09:08:00AM +0100, Russell King - ARM Linux wrote:
Currently i915/audio component works as you described. The audio is optional and HDMI graphics works without audio, while HDMI HD-audio mandates i915 graphics.
Right, but we also add additional interface on top of this to allow things like ensuring display is on when audio wants to run and now notification for events.
I don't see a reason why this can be used as single interface to bind as well as talk to display from various components, unless I missed obvious which prevent us from doing this in non i915 cases...
Maybe I can comment more specifically if I saw the code. Right now all I'm aware of is this idea without any code, and I don't like it.
Ok, i will be post my patches tomorrow. FWIW uses interface in sound/hda/hdac_i915.c for display power up/down
Side note, some of the Intel HD audio controller registers are in a power domain controlled by i915. The audio drivers needs to do power get/put, otherwise the audio driver loses its marbles when i915 switches off power. OTOH audio needs to be a good citizen so i915 can reach low power states.
Just a shout from the back, unsure if this is relevant at this point...
BR, Jani.