[PATCH] drm/i915/display: BMG supports UHBR13.5

[Murthy, Arun R]

> -----Original Message-----
> From: Jani Nikula <jani.nikula at linux.intel.com>
> Sent: Tuesday, August 27, 2024 1:11 PM
> To: Murthy, Arun R <arun.r.murthy at intel.com>; intel-xe at lists.freedesktop.org;
> intel-gfx at lists.freedesktop.org
> Cc: Murthy, Arun R <arun.r.murthy at intel.com>
> Subject: Re: [PATCH] drm/i915/display: BMG supports UHBR13.5
> 
> On Tue, 27 Aug 2024, Arun R Murthy <arun.r.murthy at intel.com> wrote:
> > UHBR20 is not supported by battlemage and the maximum link rate
> > supported is UHBR13.5
> >
> > HSD: 16023263677
> > Signed-off-by: Arun R Murthy <arun.r.murthy at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_dp.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 789c2f78826d..3232ec4b2889 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -528,6 +528,10 @@ static void
> >  intel_dp_set_source_rates(struct intel_dp *intel_dp)  {
> >  	/* The values must be in increasing order */
> > +	static const int bmg_rates[] = {
> > +		162000, 216000, 243000, 270000, 324000, 432000, 540000,
> 675000,
> > +		810000,	1000000, 1350000,
> > +	};
> >  	static const int mtl_rates[] = {
> >  		162000, 216000, 243000, 270000, 324000, 432000, 540000,
> 675000,
> >  		810000,	1000000, 2000000,
> > @@ -558,8 +562,13 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
> >  		    intel_dp->source_rates || intel_dp->num_source_rates);
> >
> >  	if (DISPLAY_VER(dev_priv) >= 14) {
> > -		source_rates = mtl_rates;
> > -		size = ARRAY_SIZE(mtl_rates);
> > +		if (IS_DGFX(dev_priv)) {
> 
> Why dgfx instead of bmg? Should be explained in commit message at the very
> least.
> 
Likewise IS_DH2 / IS_MTL we don't have IS_BMG as its Display 14.1. One of the way to differentiate this is DISPLAY < 14 are integrated and this BMG is discrete and hence using IS_DGFX() for identifying BMG platform.

Will add this in the commit message if not other comments and get Rb on this patch.

Thanks and Regards,
Arun R Murthy
-------------------

> BR,
> Jani.
> 
> > +			source_rates = bmg_rates;
> > +			size = ARRAY_SIZE(bmg_rates);
> > +		} else {
> > +			source_rates = mtl_rates;
> > +			size = ARRAY_SIZE(mtl_rates);
> > +		}
> >  		max_rate = mtl_max_source_rate(intel_dp);
> >  	} else if (DISPLAY_VER(dev_priv) >= 11) {
> >  		source_rates = icl_rates;
> 
> --
> Jani Nikula, Intel