[Intel-gfx] [PATCH] drm/i915/icl: Fix clockgating issue when using scalars

[Sripada, Radhakrishna]

On Mon, 2019-03-18 at 15:30 +0200, Ville Syrjälä wrote:
> On Fri, Mar 15, 2019 at 03:18:38PM -0700, Radhakrishna Sripada wrote:
> > Fixes the clock-gating issue when pipe scaling is enabled.
> > (Lineage #2006604312)
> > 
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > Cc: Aditya Swarup <aditya.swarup at intel.com>
> > Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com
> > >
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 17 ++++++++++++++++-
> >  1 file changed, 16 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > b/drivers/gpu/drm/i915/intel_display.c
> > index 61acbaf2af75..97344cca89c4 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -5193,9 +5193,17 @@ static int skl_update_scaler_plane(struct
> > intel_crtc_state *crtc_state,
> >  static void skylake_scaler_disable(struct intel_crtc *crtc)
> >  {
> >  	int i;
> > +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> > +	i915_reg_t reg = CLKGATE_DIS_PSL(crtc->pipe);
> >  
> >  	for (i = 0; i < crtc->num_scalers; i++)
> >  		skl_detach_scaler(crtc, i);
> > +
> > +	/*
> > +	 * Wa_2006604312:icl
> > +	 */
> > +	if (IS_ICELAKE(dev_priv))
> > +		I915_WRITE(reg, I915_READ(reg) & ~DPFR_GATING_DIS);
> 
> The register doesn't appear to be double buffered so I don't think we
> should be doing this here. Instead it should be be somewhere around
> the
> pre/port plane update stuff.
Sure would work on the lines of Display WA #827. Did not think of the
register not being double buffered. Thanks for pointing it out.
> 
> >  }
> >  
> >  static void skylake_pfit_enable(const struct intel_crtc_state
> > *crtc_state)
> > @@ -5205,6 +5213,7 @@ static void skylake_pfit_enable(const struct
> > intel_crtc_state *crtc_state)
> >  	enum pipe pipe = crtc->pipe;
> >  	const struct intel_crtc_scaler_state *scaler_state =
> >  		&crtc_state->scaler_state;
> > +	i915_reg_t reg = CLKGATE_DIS_PSL(pipe);
> >  
> >  	if (crtc_state->pch_pfit.enabled) {
> >  		u16 uv_rgb_hphase, uv_rgb_vphase;
> > @@ -5232,6 +5241,12 @@ static void skylake_pfit_enable(const struct
> > intel_crtc_state *crtc_state)
> >  			      PS_Y_PHASE(0) |
> > PS_UV_RGB_PHASE(uv_rgb_hphase));
> >  		I915_WRITE(SKL_PS_WIN_POS(pipe, id), crtc_state-
> > >pch_pfit.pos);
> >  		I915_WRITE(SKL_PS_WIN_SZ(pipe, id), crtc_state-
> > >pch_pfit.size);
> > +
> > +		/*
> > +		 * Wa_2006604312:icl
> > +		*/
> > +		if (IS_ICELAKE(dev_priv))
> > +			I915_WRITE(reg, I915_READ(reg) |
> > DPFR_GATING_DIS);
> >  	}
> >  }
> >  
> > @@ -5972,7 +5987,7 @@ static void haswell_crtc_enable(struct
> > intel_crtc_state *pipe_config,
> >  
> >  	/* Display WA #1180: WaDisableScalarClockGating: glk, cnl */
> >  	psl_clkgate_wa = (IS_GEMINILAKE(dev_priv) ||
> > IS_CANNONLAKE(dev_priv)) &&
> > -			 pipe_config->pch_pfit.enabled;
> > +			  pipe_config->pch_pfit.enabled;
> 
> Unrelated change.
My bad will omit in the next rev.

-Radhakrishna(RK) Sripada
> 
> >  	if (psl_clkgate_wa)
> >  		glk_pipe_scaler_clock_gating_wa(dev_priv, pipe, true);
> >  
> > -- 
> > 2.20.0.rc2.7.g965798d1f299
> > 
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> 
>