drm/i915/psr: Implement Wa_14015648006

PSR WM optimization should be disabled based on any wm level being
disabled. Also same WA should be applied for ICL as well.

Bspec: 71580

v5:
 - Set in pre plane hook and clear in post plane hook
v4:
 - Handle mode change in psr enable/disable
 - Handle wm_level_disable changes separately in pre plane hook
v3:
 - Split patch
v2:
 - set/clear chicken bit in post_plane_update
 - apply for ICL as well
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230329150703.432072-4-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -1157,6 +1157,7 @@ struct intel_crtc_state {
 	bool has_psr2;
 	bool enable_psr2_sel_fetch;
 	bool req_psr2_sdp_prior_scanline;
+	bool wm_level_disabled;
 	u32 dc3co_exitline;
 	u16 su_y_granularity;
 	struct drm_dp_vsc_sdp psr_vsc;

drivers/gpu/drm/i915/display/intel_psr.c

@@ -1136,6 +1136,7 @@ static u32 wa_16013835468_bit_get(struct intel_dp *intel_dp)
 
 /*
  * Wa_16013835468
+ * Wa_14015648006
  */
 static void wm_optimization_wa(struct intel_dp *intel_dp,
 			       const struct intel_crtc_state *crtc_state)
@@ -1143,6 +1144,11 @@ static void wm_optimization_wa(struct intel_dp *intel_dp,
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 	bool set_wa_bit = false;
 
+	/* Wa_14015648006 */
+	if (IS_MTL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_B0) ||
+	    IS_DISPLAY_VER(dev_priv, 11, 13))
+		set_wa_bit |= crtc_state->wm_level_disabled;
+
 	/* Wa_16013835468 */
 	if (DISPLAY_VER(dev_priv) == 12)
 		set_wa_bit |= crtc_state->hw.adjusted_mode.crtc_vblank_start !=
@@ -1197,6 +1203,7 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
 
 	/*
 	 * Wa_16013835468
+	 * Wa_14015648006
 	 */
 	wm_optimization_wa(intel_dp, crtc_state);
 
@@ -1374,8 +1381,9 @@ static void intel_psr_disable_locked(struct intel_dp *intel_dp)
 
 	/*
 	 * Wa_16013835468
+	 * Wa_14015648006
 	 */
-	if (DISPLAY_VER(dev_priv) == 12)
+	if (DISPLAY_VER(dev_priv) >= 11)
 		intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
 			     wa_16013835468_bit_get(intel_dp), 0);
 
@@ -1949,6 +1957,9 @@ void intel_psr_pre_plane_update(struct intel_atomic_state *state,
 
 		if (psr->enabled && needs_to_disable)
 			intel_psr_disable_locked(intel_dp);
+		else if (psr->enabled && new_crtc_state->wm_level_disabled)
+			/* Wa_14015648006 */
+			wm_optimization_wa(intel_dp, new_crtc_state);
 
 		mutex_unlock(&psr->lock);
 	}
@@ -1978,6 +1989,9 @@ static void _intel_psr_post_plane_update(const struct intel_atomic_state *state,
 
 		if (!psr->enabled && !keep_disabled)
 			intel_psr_enable_locked(intel_dp, crtc_state);
+		else if (psr->enabled && !crtc_state->wm_level_disabled)
+			/* Wa_14015648006 */
+			wm_optimization_wa(intel_dp, crtc_state);
 
 		/* Force a PSR exit when enabling CRC to avoid CRC timeouts */
 		if (crtc_state->crc_enabled && psr->enabled)

drivers/gpu/drm/i915/display/skl_watermark.c

@@ -2276,9 +2276,12 @@ static int skl_wm_check_vblank(struct intel_crtc_state *crtc_state)
 		return level;
 
 	/*
-	 * FIXME PSR needs to toggle LATENCY_REPORTING_REMOVED_PIPE_*
+	 * PSR needs to toggle LATENCY_REPORTING_REMOVED_PIPE_*
 	 * based on whether we're limited by the vblank duration.
-	 *
+	 */
+	crtc_state->wm_level_disabled = level < i915->display.wm.num_levels - 1;
+
+	/*
 	 * FIXME also related to skl+ w/a 1136 (also unimplemented as of
 	 * now) perhaps?
 	 */