[PATCH] drm/i915/psr: Implment WA to help reach PC10

Kandpal, Suraj suraj.kandpal at intel.com
Tue Sep 10 04:15:35 UTC 2024



> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Sent: Monday, September 9, 2024 7:42 PM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Shankar, Uma <uma.shankar at intel.com>;
> Hogander, Jouni <jouni.hogander at intel.com>
> Subject: Re: [PATCH] drm/i915/psr: Implment WA to help reach PC10
> 
> On Tue, Sep 03, 2024 at 01:54:50PM +0530, Suraj Kandpal wrote:
> > To reach PC10 when PKG_C_LATENCY is configure we must do the following
> > things
> > 1) Enter PSR1 only when delayed_vblank < 6 lines and DC5 can be
> > entered
> > 2) Allow PSR2 deep sleep when DC5 can be entered
> > 3) DC5 can be entered when all transocoder have either PSR1, PSR2 or
> > eDP 1.5 PR ALPM enabled and VBI is disabled and flips and pushes are
> > not happening.
> >
> > --v2
> > -Switch condition and do an early return [Jani] -Do some checks in
> > compute_config [Jani] -Do not use register reads as a method of
> > checking states for DPKGC or delayed vblank [Jani] -Use another way to
> > see is vblank interrupts are disabled or not [Jani]
> >
> > --v3
> > -Use has_psr to check if psr can be enabled or not for dc5_entry cond
> > [Uma] -Move the dc5 entry computation to psr_compute_config [Jouni]
> > -No need to change sequence of enabled and activate, so dont make
> > hsw_psr1_activate return anything [Jouni] -Use has_psr to stop psr1
> > activation [Jouni] -Use lineage no. in WA -Add the display ver
> > restrictions for WA
> >
> > --v4
> > -use more appropriate name for check_vblank_limit() [Jouni] -Cover the
> > case for idle frames when dpkgc is not configured [Jouni] -Check psr
> > only for edp [Jouni]
> >
> > WA: 22019444797
> > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > ---
> >  .../drm/i915/display/intel_display_types.h    |   2 +
> >  drivers/gpu/drm/i915/display/intel_psr.c      | 101 +++++++++++++++++-
> >  2 files changed, 102 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index fa03157554b2..6b95a59aba2e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1717,6 +1717,8 @@ struct intel_psr {
> >  	bool sink_support;
> >  	bool source_support;
> >  	bool enabled;
> > +	bool is_dpkgc_configured;
> > +	bool is_dc5_entry_possible;
> >  	bool paused;
> >  	enum pipe pipe;
> >  	enum transcoder transcoder;
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 257526362b39..6eb137ecd49f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -870,6 +870,74 @@ static u8 psr_compute_idle_frames(struct intel_dp
> *intel_dp)
> >  	return idle_frames;
> >  }
> >
> > +static bool intel_psr_check_wa_delayed_vblank(struct intel_crtc_state
> > +*crtc_state) {
> > +	struct drm_display_mode *adjusted_mode =
> > +&crtc_state->hw.adjusted_mode;
> > +
> > +	return (adjusted_mode->crtc_vblank_start -
> > +adjusted_mode->crtc_vdisplay) >= 6; }
> > +
> > +/*
> > + * PKG_C_LATENCY is configured only when DISPLAY_VER >= 20 and
> > + * VRR is not enabled
> > + */
> > +static bool intel_psr_is_dpkgc_configured(struct drm_i915_private
> > +*i915) {
> > +	struct intel_crtc *intel_crtc;
> > +
> > +	if (DISPLAY_VER(i915) < 20)
> > +		return false;
> > +
> > +	for_each_intel_crtc(&i915->drm, intel_crtc) {
> > +		struct intel_crtc_state *crtc_state;
> > +
> > +		if (!intel_crtc->active)
> > +			continue;
> > +
> > +		crtc_state = intel_crtc->config;
> 
> We are trying to remove all that old junk. Please do not use.
> 

Hi Ville this has already been taken care of in the latest revision

Regards,
Suraj Kandpal
> > +
> > +		if (crtc_state->vrr.enable)
> > +			return false;
> > +	}
> > +
> > +	return true;
> > +}
> > +
> > +/*
> > + * DC5 entry is only possible if vblank interrupt is disabled
> > + * and either psr1, psr2, edp 1.5 pr alpm is enabled on all
> > + * enabled encoders.
> > + */
> > +static bool
> > +intel_psr_is_dc5_entry_possible(struct drm_i915_private *i915,
> > +				struct intel_crtc_state *crtc_state) {
> > +	struct intel_crtc *intel_crtc;
> > +
> > +	if (!crtc_state->has_psr)
> > +		return false;
> > +
> > +	for_each_intel_crtc(&i915->drm, intel_crtc) {
> > +		struct drm_crtc *crtc = &intel_crtc->base;
> > +		struct drm_vblank_crtc *vblank;
> > +		struct intel_encoder *encoder;
> > +
> > +		if (!intel_crtc->active)
> > +			continue;
> > +
> > +		vblank = drm_crtc_vblank_crtc(crtc);
> > +
> > +		if (vblank->enabled)
> > +			return false;
> > +
> > +		for_each_encoder_on_crtc(&i915->drm, crtc, encoder)
> > +			if (encoder->type != INTEL_OUTPUT_EDP)
> > +				return false;
> > +	}
> > +
> > +	return true;
> > +}
> > +
> >  static void hsw_activate_psr1(struct intel_dp *intel_dp)  {
> >  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp); @@ -980,7
> > +1048,11 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
> >  	u32 val = EDP_PSR2_ENABLE;
> >  	u32 psr_val = 0;
> >
> > -	val |= EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> > +	/* Wa_22019444797 */
> > +	if (DISPLAY_VER(dev_priv) != 20 ||
> > +	    !intel_dp->psr.is_dpkgc_configured ||
> > +	    intel_dp->psr.is_dc5_entry_possible)
> > +		val |=
> EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> >
> >  	if (DISPLAY_VER(dev_priv) < 14 && !IS_ALDERLAKE_P(dev_priv))
> >  		val |= EDP_SU_TRACK_ENABLE;
> > @@ -1595,6 +1667,32 @@ _panel_replay_compute_config(struct intel_dp
> *intel_dp,
> >  	return true;
> >  }
> >
> > +static void wa_22019444797(struct intel_dp *intel_dp,
> > +			   struct intel_crtc_state *crtc_state) {
> > +	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> > +
> > +	if (DISPLAY_VER(i915) != 20)
> > +		return;
> > +
> > +	intel_dp->psr.is_dpkgc_configured =
> > +		intel_psr_is_dpkgc_configured(i915);
> > +	intel_dp->psr.is_dc5_entry_possible =
> > +		intel_psr_is_dc5_entry_possible(i915, crtc_state);
> > +
> > +	/* PSR2 not handled here. Wa not needed for Panel Replay */
> > +	if (crtc_state->has_sel_update || crtc_state->has_panel_replay)
> > +		return;
> > +
> > +	if (intel_dp->psr.is_dpkgc_configured &&
> > +	    !(intel_psr_check_wa_delayed_vblank(crtc_state) ||
> > +	      intel_dp->psr.is_dc5_entry_possible)) {
> > +		drm_dbg_kms(&i915->drm,
> > +			    "PSR1 not enabled as it doesn't meet requirements of
> WA: 22019444797\n");
> > +		crtc_state->has_psr = false;
> > +	}
> > +}
> > +
> >  void intel_psr_compute_config(struct intel_dp *intel_dp,
> >  			      struct intel_crtc_state *crtc_state,
> >  			      struct drm_connector_state *conn_state) @@ -
> 1641,6 +1739,7
> > @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
> >  		return;
> >
> >  	crtc_state->has_sel_update = intel_sel_update_config_valid(intel_dp,
> > crtc_state);
> > +	wa_22019444797(intel_dp, crtc_state);
> >  }
> >
> >  void intel_psr_get_config(struct intel_encoder *encoder,
> > --
> > 2.43.2
> 
> --
> Ville Syrjälä
> Intel


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