Re: [RFC] Runtime display PM for VLV/BYT

Daniel Vetter
2013-10-15T22:09:15Z

On Tue, Oct 15, 2013 at 8:15 PM, Imre Deak <imre.deak@intel.com> wrote:
> Related to this: I made intel_encoder_get_hw_state() only check if the
> power well is on and return false if it's not to indicate that the
> encoder is off. I also thought of doing the same as you and take a ref
> instead, not sure what's the right way. Maybe doing the readout only if
> the power is on, but also making sure we have a reference in this case?
> So with a new helper we'd have in intel_encoder_get_hw_state():

I think the approach we've quickly discussed in today's call is
probably simplest: We grab a temporary reference to all the display
power wells around all the dpms/modeset functions and ignore any power
well checks on top of that. The hw will (well, should) be in the power
on default state, so nothing should magically turn on if we don't want
that.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch