drm/i915/alpm: Enable lobf from source in ALPM_CTL

Set the Link Off Between Frames Enable bit in ALPM_CTL register.

Note: Lobf need to be enabled adaptive sync fixed refresh mode
where vmin = vmax = flipline, which will arise after cmmr feature
enablement. Will add enabling sequence in a separate patch.

v1: Initial version.
v2: Condition check modified in alpm_configure(). [Jouni]
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240529200742.1694401-6-animesh.manna@intel.com

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

@@ -304,10 +304,11 @@ void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
 		(first_sdp_position + waketime_in_lines);
 }
 
-static void lnl_alpm_configure(struct intel_dp *intel_dp)
+static void lnl_alpm_configure(struct intel_dp *intel_dp,
+			       const struct intel_crtc_state *crtc_state)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
-	enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
+	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
 	u32 alpm_ctl;
 
 	if (DISPLAY_VER(dev_priv) < 20 || (!intel_dp->psr.sel_update_enabled &&
@@ -318,7 +319,8 @@ static void lnl_alpm_configure(struct intel_dp *intel_dp)
 	 * Panel Replay on eDP is always using ALPM aux less. I.e. no need to
 	 * check panel support at this point.
 	 */
-	if (intel_dp->psr.panel_replay_enabled && intel_dp_is_edp(intel_dp)) {
+	if ((intel_dp->psr.panel_replay_enabled && intel_dp_is_edp(intel_dp)) ||
+	    (crtc_state->has_lobf && intel_alpm_aux_less_wake_supported(intel_dp))) {
 		alpm_ctl = ALPM_CTL_ALPM_ENABLE |
 			ALPM_CTL_ALPM_AUX_LESS_ENABLE |
 			ALPM_CTL_AUX_LESS_SLEEP_HOLD_TIME_50_SYMBOLS;
@@ -345,12 +347,16 @@ static void lnl_alpm_configure(struct intel_dp *intel_dp)
 			ALPM_CTL_EXTENDED_FAST_WAKE_TIME(intel_dp->alpm_parameters.fast_wake_lines);
 	}
 
+	if (crtc_state->has_lobf)
+		alpm_ctl |= ALPM_CTL_LOBF_ENABLE;
+
 	alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(intel_dp->alpm_parameters.check_entry_lines);
 
 	intel_de_write(dev_priv, ALPM_CTL(dev_priv, cpu_transcoder), alpm_ctl);
 }
 
-void intel_alpm_configure(struct intel_dp *intel_dp)
+void intel_alpm_configure(struct intel_dp *intel_dp,
+			  const struct intel_crtc_state *crtc_state)
 {
-	lnl_alpm_configure(intel_dp);
+	lnl_alpm_configure(intel_dp, crtc_state);
 }

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

@@ -18,6 +18,6 @@ bool intel_alpm_compute_params(struct intel_dp *intel_dp,
 void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
 				    struct intel_crtc_state *crtc_state,
 				    struct drm_connector_state *conn_state);
-void intel_alpm_configure(struct intel_dp *intel_dp);
-
+void intel_alpm_configure(struct intel_dp *intel_dp,
+			  const struct intel_crtc_state *crtc_state);
 #endif

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

@@ -1685,7 +1685,7 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
 			     IGNORE_PSR2_HW_TRACKING : 0);
 
 	if (intel_dp_is_edp(intel_dp))
-		intel_alpm_configure(intel_dp);
+		intel_alpm_configure(intel_dp, crtc_state);
 
 	/*
 	 * Wa_16013835468