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

Jani Nikula jani.nikula at linux.intel.com
Wed Oct 9 14:45:31 UTC 2024


On Sun, 06 Oct 2024, Suraj Kandpal <suraj.kandpal at intel.com> 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
> -Add debug prints
>
> WA: 22019444797
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c      |   3 +
>  .../drm/i915/display/intel_display_types.h    |   3 +
>  drivers/gpu/drm/i915/display/intel_psr.c      | 117 +++++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_psr.h      |   2 +
>  4 files changed, 124 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index fe1ded6707f9..cbd71c136c8d 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4368,6 +4368,9 @@ static int intel_ddi_compute_config_late(struct intel_encoder *encoder,
>  			port_sync_transcoders & ~BIT(crtc_state->cpu_transcoder);
>  	}
>  
> +	if (intel_encoder_is_dp(encoder))
> +		intel_psr_compute_config_late(encoder, crtc_state);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 17fc21f6ae36..7fb3eeb0e0f2 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1576,6 +1576,9 @@ struct intel_psr {
>  #define I915_PSR_DEBUG_PANEL_REPLAY_DISABLE	0x40
>  
>  	u32 debug;
> +	bool is_dpkgc_configured;
> +	bool is_dc5_entry_possible;
> +	bool is_wa_delayed_vblank_limit;
>  	bool sink_support;
>  	bool source_support;
>  	bool enabled;
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index 8e9f068b9b2b..9b77045df228 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -26,6 +26,7 @@
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_damage_helper.h>
>  #include <drm/drm_debugfs.h>
> +#include <drm/drm_vblank.h>
>  
>  #include "i915_drv.h"
>  #include "i915_reg.h"
> @@ -896,6 +897,82 @@ static u8 psr_compute_idle_frames(struct intel_dp *intel_dp)
>  	return idle_frames;
>  }
>  
> +static bool
> +intel_psr_check_wa_delayed_vblank(const struct drm_display_mode *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 intel_display *display,
> +					  struct intel_crtc_state *crtc_state)
> +{
> +	if (DISPLAY_VER(display) < 20 || crtc_state->vrr.enable)
> +		return false;
> +
> +	return true;
> +}
> +
> +static bool wa_22019444797_psr1_check(const struct intel_crtc_state *crtc_state,
> +				      struct intel_psr *psr)
> +{
> +	struct intel_display *display = to_intel_display(crtc_state);
> +
> +	if (DISPLAY_VER(display) == 20 && psr->is_dpkgc_configured &&
> +	    (psr->is_wa_delayed_vblank_limit || !psr->is_dc5_entry_possible) &&
> +	   !crtc_state->has_sel_update && !crtc_state->has_panel_replay) {
> +		drm_dbg_kms(display->drm,
> +			    "Wa 22019444797 requirement met PSR1 disabled\n");
> +		return true;
> +	} else {
> +		return false;
> +	}
> +}
> +
> +/*
> + * 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 intel_display *display,
> +				struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_crtc *intel_crtc;
> +
> +	if ((display->power.domains.target_dc_state &
> +	     DC_STATE_EN_UPTO_DC5_DC6_MASK) == 0)
> +		return false;
> +
> +	if (!crtc_state->has_psr && !crtc_state->has_sel_update &&
> +	    !crtc_state->has_panel_replay)
> +		return false;
> +
> +	for_each_intel_crtc(display->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(display->drm, crtc, encoder)
> +			if (encoder->type != INTEL_OUTPUT_EDP ||
> +			    !CAN_PSR(enc_to_intel_dp(encoder)))
> +				return false;
> +	}
> +
> +	return true;
> +}
> +
>  static void hsw_activate_psr1(struct intel_dp *intel_dp)
>  {
>  	struct intel_display *display = to_intel_display(intel_dp);
> @@ -1008,7 +1085,18 @@ 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
> +	 * TODO: Disable idle frames when vblank gets enabled while
> +	 * PSR2 is enabled
> +	 */
> +	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));
> +	else
> +		drm_dbg_kms(display->drm,
> +			    "Wa 22019444797 requirement met PSR2 deep sleep disabled\n");
>  
>  	if (DISPLAY_VER(display) < 14 && !IS_ALDERLAKE_P(dev_priv))
>  		val |= EDP_SU_TRACK_ENABLE;
> @@ -1686,6 +1774,24 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
>  	crtc_state->has_sel_update = intel_sel_update_config_valid(intel_dp, crtc_state);
>  }
>  
> +void intel_psr_compute_config_late(struct intel_encoder *intel_encoder,
> +				   struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_display *display = to_intel_display(intel_encoder);
> +	struct intel_dp *dp = enc_to_intel_dp(intel_encoder);
> +
> +	if (DISPLAY_VER(display) == 20) {
> +		mutex_lock(&dp->psr.lock);
> +		dp->psr.is_dpkgc_configured =
> +			intel_psr_is_dpkgc_configured(display, crtc_state);
> +		dp->psr.is_dc5_entry_possible =
> +			intel_psr_is_dc5_entry_possible(display, crtc_state);
> +		dp->psr.is_wa_delayed_vblank_limit =
> +			intel_psr_check_wa_delayed_vblank(&crtc_state->hw.adjusted_mode);

Compute config should only change the crtc state.

BR,
Jani.

> +		mutex_unlock(&dp->psr.lock);
> +	}
> +}
> +
>  void intel_psr_get_config(struct intel_encoder *encoder,
>  			  struct intel_crtc_state *pipe_config)
>  {
> @@ -2742,6 +2848,7 @@ void intel_psr_pre_plane_update(struct intel_atomic_state *state,
>  		 * - Changing between PSR versions
>  		 * - Region Early Transport changing
>  		 * - Display WA #1136: skl, bxt
> +		 * - Display WA_22019444797
>  		 */
>  		needs_to_disable |= intel_crtc_needs_modeset(new_crtc_state);
>  		needs_to_disable |= !new_crtc_state->has_psr;
> @@ -2751,6 +2858,8 @@ void intel_psr_pre_plane_update(struct intel_atomic_state *state,
>  			psr->su_region_et_enabled;
>  		needs_to_disable |= DISPLAY_VER(i915) < 11 &&
>  			new_crtc_state->wm_level_disabled;
> +		/* TODO: Disable PSR1 when vblank gets enabled while PSR1 is enabled */
> +		needs_to_disable |= wa_22019444797_psr1_check(new_crtc_state, psr);
>  
>  		if (psr->enabled && needs_to_disable)
>  			intel_psr_disable_locked(intel_dp);
> @@ -2791,6 +2900,12 @@ void intel_psr_post_plane_update(struct intel_atomic_state *state,
>  		keep_disabled |= DISPLAY_VER(display) < 11 &&
>  			crtc_state->wm_level_disabled;
>  
> +		/*
> +		 * Wa_22019444797
> +		 * TODO: Disable PSR1 when vblank gets enabled while PSR1 is enabled
> +		 */
> +		keep_disabled |= wa_22019444797_psr1_check(crtc_state, psr);
> +
>  		if (!psr->enabled && !keep_disabled)
>  			intel_psr_enable_locked(intel_dp, crtc_state);
>  		else if (psr->enabled && !crtc_state->wm_level_disabled)
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
> index 5f26f61f82aa..e0fa04952393 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.h
> +++ b/drivers/gpu/drm/i915/display/intel_psr.h
> @@ -47,6 +47,8 @@ void intel_psr_init(struct intel_dp *intel_dp);
>  void intel_psr_compute_config(struct intel_dp *intel_dp,
>  			      struct intel_crtc_state *crtc_state,
>  			      struct drm_connector_state *conn_state);
> +void intel_psr_compute_config_late(struct intel_encoder *intel_encoder,
> +				   struct intel_crtc_state *crtc_state);
>  void intel_psr_get_config(struct intel_encoder *encoder,
>  			  struct intel_crtc_state *pipe_config);
>  void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir);

-- 
Jani Nikula, Intel


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