[PATCH v3 08/12] drm/i915/alpm: Move port alpm configuration

Jouni Högander jouni.hogander at intel.com
Wed May 21 09:32:36 UTC 2025


It is specified in Bspec where port alpm configuration is supposed to be
performed. Change accordingly.

v2:
  - drop HAS reference
  - ensure PORT_ALPM registers are not writen on older platform

Bspec: 68849
Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_alpm.c    | 48 ++++++++++++--------
 drivers/gpu/drm/i915/display/intel_alpm.h    |  2 +
 drivers/gpu/drm/i915/display/intel_cx0_phy.c |  1 +
 drivers/gpu/drm/i915/display/intel_ddi.c     |  6 +++
 4 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index bbcf510b0c25..dfdde8e4eabe 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -336,7 +336,6 @@ static void lnl_alpm_configure(struct intel_dp *intel_dp,
 {
 	struct intel_display *display = to_intel_display(intel_dp);
 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
-	enum port port = dp_to_dig_port(intel_dp)->base.port;
 	u32 alpm_ctl;
 
 	if (DISPLAY_VER(display) < 20 || (!intel_psr_needs_alpm(intel_dp, crtc_state) &&
@@ -368,23 +367,6 @@ static void lnl_alpm_configure(struct intel_dp *intel_dp,
 				       pr_alpm_ctl);
 		}
 
-		intel_de_write(display,
-			       PORT_ALPM_CTL(port),
-			       PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE |
-			       PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
-			       PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0) |
-			       PORT_ALPM_CTL_SILENCE_PERIOD(
-				       intel_dp->alpm_parameters.silence_period_sym_clocks));
-
-		intel_de_write(display,
-			       PORT_ALPM_LFPS_CTL(port),
-			       PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(10) |
-			       PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
-				       intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
-			       PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
-				       intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
-			       PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
-				       intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms));
 	} else {
 		alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
 			ALPM_CTL_EXTENDED_FAST_WAKE_TIME(intel_dp->alpm_parameters.fast_wake_lines);
@@ -408,6 +390,36 @@ void intel_alpm_configure(struct intel_dp *intel_dp,
 	intel_dp->alpm_parameters.transcoder = crtc_state->cpu_transcoder;
 }
 
+void intel_alpm_port_configure(struct intel_dp *intel_dp,
+			       const struct intel_crtc_state *crtc_state)
+{
+	struct intel_display *display = to_intel_display(intel_dp);
+	enum port port = dp_to_dig_port(intel_dp)->base.port;
+	u32 alpm_ctl_val = 0, lfps_ctl_val = 0;
+
+	if (DISPLAY_VER(display) < 20)
+		return;
+
+	if (intel_alpm_is_alpm_aux_less(intel_dp, crtc_state)) {
+		alpm_ctl_val = PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE |
+			PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
+			PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0) |
+			PORT_ALPM_CTL_SILENCE_PERIOD(
+				intel_dp->alpm_parameters.silence_period_sym_clocks);
+		lfps_ctl_val = PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(10) |
+			PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
+				intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
+			PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
+				intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
+			PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
+				intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms);
+	}
+
+	intel_de_write(display, PORT_ALPM_CTL(port), alpm_ctl_val);
+
+	intel_de_write(display, PORT_ALPM_LFPS_CTL(port), lfps_ctl_val);
+}
+
 void intel_alpm_pre_plane_update(struct intel_atomic_state *state,
 				 struct intel_crtc *crtc)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h b/drivers/gpu/drm/i915/display/intel_alpm.h
index 86f4d5ab1981..a861c20b5d79 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.h
+++ b/drivers/gpu/drm/i915/display/intel_alpm.h
@@ -27,6 +27,8 @@ void intel_alpm_enable_sink(struct intel_dp *intel_dp,
 			    const struct intel_crtc_state *crtc_state);
 void intel_alpm_pre_plane_update(struct intel_atomic_state *state,
 				 struct intel_crtc *crtc);
+void intel_alpm_port_configure(struct intel_dp *intel_dp,
+			       const struct intel_crtc_state *crtc_state);
 void intel_alpm_post_plane_update(struct intel_atomic_state *state,
 				  struct intel_crtc *crtc);
 void intel_alpm_lobf_debugfs_add(struct intel_connector *connector);
diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
index a82b93cbc81d..91118d115fd3 100644
--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
@@ -10,6 +10,7 @@
 
 #include "i915_reg.h"
 #include "i915_utils.h"
+#include "intel_alpm.h"
 #include "intel_cx0_phy.h"
 #include "intel_cx0_phy_regs.h"
 #include "intel_ddi.h"
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 0e6d618b5356..65ab012c3eae 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3743,6 +3743,12 @@ static void mtl_ddi_prepare_link_retrain(struct intel_dp *intel_dp,
 
 	intel_ddi_buf_enable(encoder, intel_dp->DP);
 	intel_dp->DP |= DDI_BUF_CTL_ENABLE;
+
+	/*
+	 * 6.k If AUX-Less ALPM is going to be enabled
+	 *     i. Configure PORT_ALPM_CTL and PORT_ALPM_LFPS_CTL here
+	 */
+	intel_alpm_port_configure(intel_dp, crtc_state);
 }
 
 static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp,
-- 
2.43.0



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