[Intel-gfx] [PATCH v4 19/25] drm/i915/dsc: Add a power domain for VDSC on eDP/MIPI DSI

[Manasi Navare]

On Tue, Sep 18, 2018 at 10:12:24PM +0300, Ville Syrjälä wrote:
> On Tue, Sep 18, 2018 at 12:04:35PM -0700, Manasi Navare wrote:
> > Thanks Imre for your review comments. Please find the comments below:
> > 
> > On Fri, Sep 14, 2018 at 01:55:00PM +0300, Imre Deak wrote:
> > > On Tue, Sep 11, 2018 at 05:56:01PM -0700, Manasi Navare wrote:
> > > > On Icelake, a separate power well PG2 is created for
> > > > VDSC engine used for eDP/MIPI DSI. This patch adds a new
> > > > display power domain for Power well 2.
> > > > 
> > > > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > > Cc: Imre Deak <imre.deak at intel.com>
> > > > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/intel_display.h    |  1 +
> > > >  drivers/gpu/drm/i915/intel_runtime_pm.c | 12 ++++++------
> > > >  2 files changed, 7 insertions(+), 6 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/intel_display.h b/drivers/gpu/drm/i915/intel_display.h
> > > > index 3fe52788b4cf..bef71d27cdfe 100644
> > > > --- a/drivers/gpu/drm/i915/intel_display.h
> > > > +++ b/drivers/gpu/drm/i915/intel_display.h
> > > > @@ -256,6 +256,7 @@ enum intel_display_power_domain {
> > > >  	POWER_DOMAIN_MODESET,
> > > >  	POWER_DOMAIN_GT_IRQ,
> > > >  	POWER_DOMAIN_INIT,
> > > > +	POWER_DOMAIN_VDSC_EDP_MIPI,
> > > 
> > > This is better named VDSC_PIPE_A. The other pipes have also VDSC
> > > functionality which could be on separate power wells in the future.
> > >
> > 
> > Yea naming it as VDSC_PIPE_A makes sense since eDP/MIPI DSI on Pipe A
> > will use this VDSC power well.
> > I will change this in the next revision.
> 
> Isn't the VDSC in the transcoder for now though? And I guess it's
> moving to the pipe later?

VDSC engine is attached to the eDP/DSI transcoders and this gets used
for eDP/DSI VDSC on Pipe A.
So we could call it VDSC_PIPE_A since VDSC on Pipe A for eDP/DSI
will use this power well. But may be we should add a comment that
this is only for eDP/DSI on Pipe A since ICL does not support
VDSC on DP on Pipe A

What do you think?

Manasi

> 
> If we call it PIPE_A then it's going to a bit confusing when we
> use it with pipe B or C. Needs at least clear comments in the code
> why we're doing something that looks like nonsense of the first
> glance.
> 
> -- 
> Ville Syrjälä
> Intel