[Intel-gfx] [PATCH] drm/i915/tgl: Add memory type decoding for bandwidth checking

[James Ausmus]

On Fri, Sep 20, 2019 at 03:29:06PM +0300, Ville Syrjälä wrote:
> On Thu, Sep 19, 2019 at 03:16:40PM -0700, James Ausmus wrote:
> > The memory type values have changed in TGL, so we need to translate them
> > differently than ICL.
> > 
> > BSpec: 53998
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > Signed-off-by: James Ausmus <james.ausmus at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_bw.c | 59 ++++++++++++++++++-------
> >  1 file changed, 43 insertions(+), 16 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
> > index 688858ebe4d0..11224d9a6752 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bw.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> > @@ -35,22 +35,49 @@ static int icl_pcode_read_mem_global_info(struct drm_i915_private *dev_priv,
> >  	if (ret)
> >  		return ret;
> >  
> > -	switch (val & 0xf) {
> > -	case 0:
> > -		qi->dram_type = INTEL_DRAM_DDR4;
> > -		break;
> > -	case 1:
> > -		qi->dram_type = INTEL_DRAM_DDR3;
> > -		break;
> > -	case 2:
> > -		qi->dram_type = INTEL_DRAM_LPDDR3;
> > -		break;
> > -	case 3:
> > -		qi->dram_type = INTEL_DRAM_LPDDR3;
> 
> This should be LPDDR4 actually. Doesn't really matter but would be nice
> to fix as well.

Either my git send-email config or the ML seems to be eating my original
patch mail, and it's not hitting the list, patchwork, or CI, so will
have to send a v2 anyway and I will fix this up in that.

> 
> > -		break;
> > -	default:
> > -		MISSING_CASE(val & 0xf);
> > -		break;
> > +	if (IS_GEN(dev_priv, 12)) {
> > +		switch (val & 0xf) {
> > +		case 0:
> > +			qi->dram_type = INTEL_DRAM_DDR4;
> > +			break;
> > +		case 3:
> > +			qi->dram_type = INTEL_DRAM_LPDDR4;
> > +			break;
> > +		case 4:
> > +			qi->dram_type = INTEL_DRAM_DDR3;
> > +			break;
> > +		case 5:
> > +			qi->dram_type = INTEL_DRAM_LPDDR3;
> > +			break;
> > +		case 1:
> > +		case 2:
> > +			/* Unimplemented */
> 
> Seems pointless to list these.

Will drop in v2.

> 
> The numbers match bspec. Unfortunatley I can't get tgl
> configdb to cooperate so can't double check against the
> MC register definition.
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Thanks!

-James

> 
> > +			/* fall through */
> > +		default:
> > +			MISSING_CASE(val & 0xf);
> > +			break;
> > +		}
> > +	} else if (IS_GEN(dev_priv, 11)) {
> > +		switch (val & 0xf) {
> > +		case 0:
> > +			qi->dram_type = INTEL_DRAM_DDR4;
> > +			break;
> > +		case 1:
> > +			qi->dram_type = INTEL_DRAM_DDR3;
> > +			break;
> > +		case 2:
> > +			qi->dram_type = INTEL_DRAM_LPDDR3;
> > +			break;
> > +		case 3:
> > +			qi->dram_type = INTEL_DRAM_LPDDR3;
> > +			break;
> > +		default:
> > +			MISSING_CASE(val & 0xf);
> > +			break;
> > +		}
> > +	} else {
> > +		MISSING_CASE(INTEL_GEN(dev_priv));
> > +		qi->dram_type = INTEL_DRAM_LPDDR3; /* Conservative default */
> >  	}
> >  
> >  	qi->num_channels = (val & 0xf0) >> 4;
> > -- 
> > 2.22.1
> 
> -- 
> Ville Syrjälä
> Intel