Re: [Intel-gfx] [Intel-xe] [PATCH 3/6] drm/i915: Fix comparison in intel_dram.

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Apr 03, 2023 at 01:35:40PM -0700, Matt Roper wrote:
> On Fri, Mar 31, 2023 at 12:24:16PM +0200, Maarten Lankhorst wrote:
> > Gen13 should probably be the same as gen12, not gen11.
> > 
> > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: intel-gfx@lists.freedesktop.org
> > ---
> >  drivers/gpu/drm/i915/soc/intel_dram.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/soc/intel_dram.c b/drivers/gpu/drm/i915/soc/intel_dram.c
> > index 9f0651d48d41..9649051ed8ed 100644
> > --- a/drivers/gpu/drm/i915/soc/intel_dram.c
> > +++ b/drivers/gpu/drm/i915/soc/intel_dram.c
> > @@ -548,7 +548,7 @@ static int icl_pcode_read_mem_global_info(struct drm_i915_private *dev_priv)
> 
> I don't think we need this change.  We were only reading the this pcode
> mailbox for display purposes, and even on the latest graphics version 12
> platforms we shouldn't make it into this function anymore.  Instead the
> display IP now provides this information itself so there's no need to go
> through the GT's pcode mailbox; we read it directly from display
> registers in xelpdp_get_dram_info().  It looks like this condition here
> would only matter if we had a future platform with graphics version
> higher than 12, but display version lower than 14, which seems very
> unlikely.
> 
> 
> Matt
> 
> >  	if (ret)
> >  		return ret;
> >  
> > -	if (GRAPHICS_VER(dev_priv) == 12) {
> > +	if (GRAPHICS_VER(dev_priv) >= 12) {

We should perhaps change all the checks here to DISPLAY_VER
since it's the display code that needs this information.

Though I suppose technically neither DISPLAY_VER nor
GRAPHICS_VER is entirely correct since it's really SoC
level stuff that we're looking at here. But the current 
mismash of GRAPHICS_VER and DISPLAY_VER is certainly not
helping reduce the confusion.

> >  		switch (val & 0xf) {
> >  		case 0:
> >  			dram_info->type = INTEL_DRAM_DDR4;
> > -- 
> > 2.34.1
> > 
> 
> -- 
> Matt Roper
> Graphics Software Engineer
> Linux GPU Platform Enablement
> Intel Corporation

-- 
Ville Syrjälä
Intel