[PATCH] drm/i915/dpkgc: Add VRR condition for DPKGC Enablement

[Kandpal, Suraj]

> -----Original Message-----
> From: Golani, Mitulkumar Ajitkumar
> <mitulkumar.ajitkumar.golani at intel.com>
> Sent: Thursday, July 18, 2024 9:35 PM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Manna, Animesh <animesh.manna at intel.com>; B, Jeevan
> <jeevan.b at intel.com>; Naladala, Ramanaidu
> <ramanaidu.naladala at intel.com>
> Subject: RE: [PATCH] drm/i915/dpkgc: Add VRR condition for DPKGC
> Enablement
> 
> 
> 
> > -----Original Message-----
> > From: Kandpal, Suraj <suraj.kandpal at intel.com>
> > Sent: Thursday, July 11, 2024 10:19 AM
> > To: intel-gfx at lists.freedesktop.org
> > Cc: Manna, Animesh <animesh.manna at intel.com>; B, Jeevan
> > <jeevan.b at intel.com>; Golani, Mitulkumar Ajitkumar
> > <mitulkumar.ajitkumar.golani at intel.com>; Naladala, Ramanaidu
> > <ramanaidu.naladala at intel.com>; Kandpal, Suraj
> > <suraj.kandpal at intel.com>
> > Subject: [PATCH] drm/i915/dpkgc: Add VRR condition for DPKGC
> > Enablement
> >
> > DPKGC can now be enabled with VRR enabled if Vmin = Vmax = Flipline is
> met.
> >
> > Bspec: 68986
> > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/skl_watermark.c | 24
> > +++++++++++---------
> >  1 file changed, 13 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c
> > b/drivers/gpu/drm/i915/display/skl_watermark.c
> > index a2726364b34d..045c7cac166b 100644
> > --- a/drivers/gpu/drm/i915/display/skl_watermark.c
> > +++ b/drivers/gpu/drm/i915/display/skl_watermark.c
> > @@ -2830,17 +2830,17 @@ static int skl_wm_add_affected_planes(struct
> > intel_atomic_state *state,  }
> >
> >  /*
> > - * If Fixed Refresh Rate:
> > + * If Fixed Refresh Rate or For VRR case Vmin = Vmax = Flipline:
> >   * Program DEEP PKG_C_LATENCY Pkg C with highest valid latency from
> >   * watermark level1 and up and above. If watermark level 1 is
> >   * invalid program it with all 1's.
> >   * Program PKG_C_LATENCY Added Wake Time = DSB execution time
> > - * If Variable Refresh Rate:
> > + * If Variable Refresh Rate where Vmin != Vmax != Flipline:
> >   * Program DEEP PKG_C_LATENCY Pkg C with all 1's.
> >   * Program PKG_C_LATENCY Added Wake Time = 0
> >   */
> >  static void
> > -skl_program_dpkgc_latency(struct drm_i915_private *i915, bool
> > vrr_enabled)
> > +skl_program_dpkgc_latency(struct drm_i915_private *i915, bool
> > +enable_dpkgc)
> >  {
> >  	u32 max_latency = 0;
> >  	u32 clear = 0, val = 0;
> > @@ -2849,15 +2849,15 @@ skl_program_dpkgc_latency(struct
> > drm_i915_private *i915, bool vrr_enabled)
> >  	if (DISPLAY_VER(i915) < 20)
> >  		return;
> >
> > -	if (vrr_enabled) {
> > -		max_latency = LNL_PKG_C_LATENCY_MASK;
> > -		added_wake_time = 0;
> > -	} else {
> > +	if (enable_dpkgc) {
> >  		max_latency = skl_watermark_max_latency(i915, 1);
> >  		if (max_latency == 0)
> >  			max_latency = LNL_PKG_C_LATENCY_MASK;
> >  		added_wake_time = DSB_EXE_TIME +
> >  			i915->display.sagv.block_time_us;
> > +	} else {
> > +		max_latency = LNL_PKG_C_LATENCY_MASK;
> > +		added_wake_time = 0;
> >  	}
> >
> >  	clear |= LNL_ADDED_WAKE_TIME_MASK |
> > LNL_PKG_C_LATENCY_MASK; @@ -2873,7 +2873,7 @@
> skl_compute_wm(struct
> > intel_atomic_state *state)
> >  	struct intel_crtc *crtc;
> >  	struct intel_crtc_state __maybe_unused *new_crtc_state;
> >  	int ret, i;
> > -	bool vrr_enabled = false;
> > +	bool enable_dpkgc = false;
> >
> >  	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
> >  		ret = skl_build_pipe_wm(state, crtc); @@ -2899,11 +2899,13
> @@
> > skl_compute_wm(struct intel_atomic_state *state)
> >  		if (ret)
> >  			return ret;
> >
> > -		if (new_crtc_state->vrr.enable)
> > -			vrr_enabled = true;
> > +		if ((new_crtc_state->vrr.vmin == new_crtc_state->vrr.vmax &&
> > +		     new_crtc_state->vrr.vmin == new_crtc_state->vrr.flipline)
> ||
> 
> 	In current implementation this target to CMRR it seems.

Yes I saw Ankit's patch series which introduces vrr.is_fixed but I understand its not always set even if cmrr is in picture.
Seems like this condition is the best as it best represents the condition mentioned in bspec.

> 
> > +		    !new_crtc_state->vrr.enable)
> 	But in CMRR as well, vrr.enable is set along with vrr.enable. Any
> specific case you are targeting to ?

So either we have vmax=vmin=flipline or vrr is disabled these are the two conditions in which
Dpkgc can be enabled

Regards,
Suraj Kandpal
> 
> > +			enable_dpkgc = true;
> >  	}
> >
> > -	skl_program_dpkgc_latency(to_i915(state->base.dev), vrr_enabled);
> > +	skl_program_dpkgc_latency(to_i915(state->base.dev),
> enable_dpkgc);
> 
> >
> >  	skl_print_wm_changes(state);
> >
> > --
> > 2.43.2