[Intel-gfx] [PATCH 2/2] drm/i915/glk: Fix DMC/DC state idleness calculation

[Imre Deak]

On Tue, Oct 03, 2017 at 10:47:50AM -0700, Rodrigo Vivi wrote:
> On Tue, Oct 03, 2017 at 09:51:59AM +0000, Imre Deak wrote:
> > According to BSpec GLK like BXT needs to ignore the idle state of cores
> > before starting the DMC firmware's DC state handler.
> 
> no mention on CNL there?

No, this is only needed for BXT and GLK.

> Btw I just saw that CNL DMC seems much more like BXT than like SKL.
> Our code probably needs deeper changes...
> 
> > 
> > Fixes: dbb28b5c3d3c ("drm/i915/DMC/GLK: Load DMC on GLK")
> > Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_csr.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
> > index cdfb624eb82d..ea5d5c9645a4 100644
> > --- a/drivers/gpu/drm/i915/intel_csr.c
> > +++ b/drivers/gpu/drm/i915/intel_csr.c
> > @@ -216,7 +216,7 @@ static void gen9_set_dc_state_debugmask(struct drm_i915_private *dev_priv)
> >  
> >  	mask = DC_STATE_DEBUG_MASK_MEMORY_UP;
> >  
> > -	if (IS_BROXTON(dev_priv))
> > +	if (IS_GEN9_LP(dev_priv))
> >  		mask |= DC_STATE_DEBUG_MASK_CORES;
> 
> I saw in spec for SKL+: "This field must be set to Mask prior to enabling DC5 or DC6"
> So I believe this should be INTEL_GEN(dev_priv) >= 9... :/

No, only needed for BXT, GLK, see under BSpec "Sequences for Display C5 and C6".

> >  
> >  	/* The below bit doesn't need to be cleared ever afterwards */
> > -- 
> > 2.13.2
> >