Re: [PATCH 2/7] drm/i915: Disable compression tricks on JSL

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

On Fri, Oct 04, 2024 at 04:22:42PM +0300, Juha-Pekka Heikkila wrote:
> On 18.9.2024 17.44, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Bspec asks us to disable some compression trick on JSL. While the
> > bspec description is pretty vague it looks like this is some extra
> > trick for 10bpc+ CCS which presumably the ICL derived display engine
> > doesn't support.
> > 
> > Note that we aren't currently exposing 10bpc CCS scanout support,
> > but once that gets added this presumably becomes an issue.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >   drivers/gpu/drm/i915/gt/intel_gt_regs.h     | 1 +
> >   drivers/gpu/drm/i915/gt/intel_workarounds.c | 9 +++++++++
> >   2 files changed, 10 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> > index 57a3c83d3655..67c47c8b75fb 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> > @@ -432,6 +432,7 @@
> >   #define XEHPG_INSTDONE_GEOM_SVG			MCR_REG(0x666c)
> >   
> >   #define CACHE_MODE_0_GEN7			_MMIO(0x7000) /* IVB+ */
> > +#define   DISABLE_REPACKING_FOR_COMPRESSION	REG_BIT(15) /* jsl+ */
> >   #define   RC_OP_FLUSH_ENABLE			(1 << 0)
> >   #define   HIZ_RAW_STALL_OPT_DISABLE		(1 << 2)
> >   #define CACHE_MODE_1				_MMIO(0x7004) /* IVB+ */
> > diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > index e539a656cfc3..6972525fe6be 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > @@ -2299,6 +2299,15 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
> >   			     GEN8_RC_SEMA_IDLE_MSG_DISABLE);
> >   	}
> >   
> > +	if (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915)) {
> > +		/*
> > +		 * "Disable Repacking for Compression (masked R/W access)
> > +		 *  before rendering compressed surfaces for display."
> > +		 */
> 
> I think here would be needed the wa number mentioned since it's on all 
> the other cases.

There isn't one.

> 
> > +		wa_masked_en(wal, CACHE_MODE_0_GEN7,
> > +			     DISABLE_REPACKING_FOR_COMPRESSION);
> > +	}
> > +
> >   	if (GRAPHICS_VER(i915) == 11) {
> >   		/* This is not an Wa. Enable for better image quality */
> >   		wa_masked_en(wal,

-- 
Ville Syrjälä
Intel