[Intel-gfx] [RFC PATCH 1/3] drm/915: Add private api for power well usage

[Jesse Barnes]

On Thu, 9 May 2013 11:30:01 -0700
Jesse Barnes <jesse.barnes at intel.com> wrote:

> > The question is in which level we need power_well_*() controls.
> > If the initialization of HD-audio controller (e.g. PCI registers)
> > requires the power well on, hda_intel.c requires the calls, as this
> > patch does.  OTOH, if it's only about the HD-audio verbs, basically we
> > can push the power well calls into the codec driver,
> > i.e. patch_hdmi.c.  In the latter case, as David once suggested, we
> > can split the Haswell codec driver from patch_hdmi.c so that only the
> > new driver depends on i915.  
> 
> I think it's needed for the HDMI related MMIO regs as well, but I don't
> have a platform to test and make sure.

Sorry, HD regs, not HDMI (though the power well is needed for those
too :).  AFAIK all the registers for interacting with HDMI audio on the
graphics device require the power well to be up in order to be accessed.

-- 
Jesse Barnes, Intel Open Source Technology Center