[PATCH 05/10] drm/i915/psr: Consider SCL lines when validating vblank for wake latency

[Ankit Nautiyal <ankit.k.nautiyal@intel.com>]

Panel Replay and PSR2 selective update require sufficient vblank duration
to accommodate wake latencies. However, the current
wake_lines_fit_into_vblank() logic does not account for the minimum
Set Context Latency (SCL) lines.

Separate out _intel_psr_min_set_context_latency() to compute the minimum
SCL requirement based on platform and feature usage.

The alpm_config_valid() helper is updated to pass the necessary context for
determining whether Panel Replay or PSR2 selective update is enabled.

v2: While calling alpm_config_valid() for selective_update use false flag
    instead of has_panel_replay. (Jouni)
v3: Correct ordering of the panel_replay, sel_update flags. (Jouni)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 102 ++++++++++++++---------
 1 file changed, 61 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 2131473cead6..1d06011a97ce 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1361,14 +1361,64 @@ static int intel_psr_entry_setup_frames(struct intel_dp *intel_dp,
 	return entry_setup_frames;
 }
 
+static
+int _intel_psr_min_set_context_latency(const struct intel_crtc_state *crtc_state,
+				       bool needs_panel_replay,
+				       bool needs_sel_update)
+{
+	struct intel_display *display = to_intel_display(crtc_state);
+
+	if (!crtc_state->has_psr)
+		return 0;
+
+	/* Wa_14015401596 */
+	if (intel_vrr_possible(crtc_state) && IS_DISPLAY_VER(display, 13, 14))
+		return 1;
+
+	/* Rest is for SRD_STATUS needed on LunarLake and onwards */
+	if (DISPLAY_VER(display) < 20)
+		return 0;
+
+	/*
+	 * Comment on SRD_STATUS register in Bspec for LunarLake and onwards:
+	 *
+	 * To deterministically capture the transition of the state machine
+	 * going from SRDOFFACK to IDLE, the delayed V. Blank should be at least
+	 * one line after the non-delayed V. Blank.
+	 *
+	 * Legacy TG: TRANS_SET_CONTEXT_LATENCY > 0
+	 * VRR TG: TRANS_VRR_CTL[ VRR Guardband ] < (TRANS_VRR_VMAX[ VRR Vmax ]
+	 * - TRANS_VTOTAL[ Vertical Active ])
+	 *
+	 * SRD_STATUS is used only by PSR1 on PantherLake.
+	 * SRD_STATUS is used by PSR1 and Panel Replay DP on LunarLake.
+	 */
+
+	if (DISPLAY_VER(display) >= 30 && (needs_panel_replay ||
+					   needs_sel_update))
+		return 0;
+	else if (DISPLAY_VER(display) < 30 && (needs_sel_update ||
+					       intel_crtc_has_type(crtc_state,
+								   INTEL_OUTPUT_EDP)))
+		return 0;
+	else
+		return 1;
+}
+
 static bool wake_lines_fit_into_vblank(struct intel_dp *intel_dp,
 				       const struct intel_crtc_state *crtc_state,
-				       bool aux_less)
+				       bool aux_less,
+				       bool needs_panel_replay,
+				       bool needs_sel_update)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
 	int vblank = crtc_state->hw.adjusted_mode.crtc_vblank_end -
 		crtc_state->hw.adjusted_mode.crtc_vblank_start;
 	int wake_lines;
+	int scl = _intel_psr_min_set_context_latency(crtc_state,
+						     needs_panel_replay,
+						     needs_sel_update);
+	vblank -= scl;
 
 	if (aux_less)
 		wake_lines = crtc_state->alpm_state.aux_less_wake_lines;
@@ -1390,7 +1440,9 @@ static bool wake_lines_fit_into_vblank(struct intel_dp *intel_dp,
 
 static bool alpm_config_valid(struct intel_dp *intel_dp,
 			      struct intel_crtc_state *crtc_state,
-			      bool aux_less)
+			      bool aux_less,
+			      bool needs_panel_replay,
+			      bool needs_sel_update)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
 
@@ -1400,7 +1452,8 @@ static bool alpm_config_valid(struct intel_dp *intel_dp,
 		return false;
 	}
 
-	if (!wake_lines_fit_into_vblank(intel_dp, crtc_state, aux_less)) {
+	if (!wake_lines_fit_into_vblank(intel_dp, crtc_state, aux_less,
+					needs_panel_replay, needs_sel_update)) {
 		drm_dbg_kms(display->drm,
 			    "PSR2/Panel Replay not enabled, too short vblank time\n");
 		return false;
@@ -1492,7 +1545,7 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 		return false;
 	}
 
-	if (!alpm_config_valid(intel_dp, crtc_state, false))
+	if (!alpm_config_valid(intel_dp, crtc_state, false, false, true))
 		return false;
 
 	if (!crtc_state->enable_psr2_sel_fetch &&
@@ -1643,7 +1696,7 @@ _panel_replay_compute_config(struct intel_dp *intel_dp,
 		return false;
 	}
 
-	if (!alpm_config_valid(intel_dp, crtc_state, true))
+	if (!alpm_config_valid(intel_dp, crtc_state, true, true, false))
 		return false;
 
 	return true;
@@ -2371,43 +2424,10 @@ void intel_psr_trigger_frame_change_event(struct intel_dsb *dsb,
  */
 int intel_psr_min_set_context_latency(const struct intel_crtc_state *crtc_state)
 {
-	struct intel_display *display = to_intel_display(crtc_state);
-
-	if (!crtc_state->has_psr)
-		return 0;
-
-	/* Wa_14015401596 */
-	if (intel_vrr_possible(crtc_state) && IS_DISPLAY_VER(display, 13, 14))
-		return 1;
-
-	/* Rest is for SRD_STATUS needed on LunarLake and onwards */
-	if (DISPLAY_VER(display) < 20)
-		return 0;
 
-	/*
-	 * Comment on SRD_STATUS register in Bspec for LunarLake and onwards:
-	 *
-	 * To deterministically capture the transition of the state machine
-	 * going from SRDOFFACK to IDLE, the delayed V. Blank should be at least
-	 * one line after the non-delayed V. Blank.
-	 *
-	 * Legacy TG: TRANS_SET_CONTEXT_LATENCY > 0
-	 * VRR TG: TRANS_VRR_CTL[ VRR Guardband ] < (TRANS_VRR_VMAX[ VRR Vmax ]
-	 * - TRANS_VTOTAL[ Vertical Active ])
-	 *
-	 * SRD_STATUS is used only by PSR1 on PantherLake.
-	 * SRD_STATUS is used by PSR1 and Panel Replay DP on LunarLake.
-	 */
-
-	if (DISPLAY_VER(display) >= 30 && (crtc_state->has_panel_replay ||
-					   crtc_state->has_sel_update))
-		return 0;
-	else if (DISPLAY_VER(display) < 30 && (crtc_state->has_sel_update ||
-					       intel_crtc_has_type(crtc_state,
-								   INTEL_OUTPUT_EDP)))
-		return 0;
-	else
-		return 1;
+	return _intel_psr_min_set_context_latency(crtc_state,
+						  crtc_state->has_panel_replay,
+						  crtc_state->has_sel_update);
 }
 
 static u32 man_trk_ctl_enable_bit_get(struct intel_display *display)
-- 
2.45.2