[PATCH v2 03/38] drm/msm/dp: break up dp_display_enable into two parts

Yongxing Mou quic_yongmou at quicinc.com
Mon Jun 9 12:21:22 UTC 2025


From: Abhinav Kumar <quic_abhinavk at quicinc.com>

dp_display_enable() currently re-trains the link if needed
and then enables the pixel clock, programs the controller to
start sending the pixel stream. Splite these two parts into
prepare/enable APIs, to support MST bridges_enable inserte
the MST payloads funcs between enable stream_clks and programe
register.

Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
Signed-off-by: Yongxing Mou <quic_yongmou at quicinc.com>
---
 drivers/gpu/drm/msm/dp/dp_ctrl.c    | 57 +++++++++++++--------
 drivers/gpu/drm/msm/dp/dp_ctrl.h    |  3 +-
 drivers/gpu/drm/msm/dp/dp_display.c | 99 +++++++++++++++++++++++++++----------
 drivers/gpu/drm/msm/dp/dp_display.h |  1 +
 4 files changed, 111 insertions(+), 49 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index a50bfafbb4ea85c114c958ea0ed24362a1f23136..1e13ca81b0155a37a4ed7a2e83c918293d703a37 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1980,40 +1980,61 @@ static int msm_dp_ctrl_link_retrain(struct msm_dp_ctrl_private *ctrl)
 	return msm_dp_ctrl_setup_main_link(ctrl, &training_step);
 }
 
-int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train)
+int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train)
 {
 	int ret = 0;
-	bool mainlink_ready = false;
 	struct msm_dp_ctrl_private *ctrl;
-	unsigned long pixel_rate;
-	unsigned long pixel_rate_orig;
 
 	if (!msm_dp_ctrl)
 		return -EINVAL;
 
 	ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, msm_dp_ctrl);
 
-	pixel_rate = pixel_rate_orig = ctrl->panel->msm_dp_mode.drm_mode.clock;
-
-	if (msm_dp_ctrl->wide_bus_en || ctrl->panel->msm_dp_mode.out_fmt_is_yuv_420)
-		pixel_rate >>= 1;
-
-	drm_dbg_dp(ctrl->drm_dev, "rate=%d, num_lanes=%d, pixel_rate=%lu\n",
-		ctrl->link->link_params.rate,
-		ctrl->link->link_params.num_lanes, pixel_rate);
+	drm_dbg_dp(ctrl->drm_dev, "rate=%d, num_lanes=%d\n",
+		   ctrl->link->link_params.rate,
+		   ctrl->link->link_params.num_lanes);
 
 	drm_dbg_dp(ctrl->drm_dev,
-		"core_clk_on=%d link_clk_on=%d stream_clk_on=%d\n",
-		ctrl->core_clks_on, ctrl->link_clks_on, ctrl->stream_clks_on);
+		   "core_clk_on=%d link_clk_on=%d stream_clk_on=%d\n",
+		   ctrl->core_clks_on, ctrl->link_clks_on, ctrl->stream_clks_on);
 
 	if (!ctrl->link_clks_on) { /* link clk is off */
 		ret = msm_dp_ctrl_enable_mainlink_clocks(ctrl);
 		if (ret) {
 			DRM_ERROR("Failed to start link clocks. ret=%d\n", ret);
-			goto end;
+			return ret;
 		}
 	}
 
+	if (force_link_train || !msm_dp_ctrl_channel_eq_ok(ctrl))
+		msm_dp_ctrl_link_retrain(ctrl);
+
+	/* stop txing train pattern to end link training */
+	msm_dp_ctrl_clear_training_pattern(ctrl, DP_PHY_DPRX);
+
+	return ret;
+}
+
+int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl)
+{
+	int ret = 0;
+	bool mainlink_ready = false;
+	struct msm_dp_ctrl_private *ctrl;
+	unsigned long pixel_rate;
+	unsigned long pixel_rate_orig;
+
+	if (!msm_dp_ctrl)
+		return -EINVAL;
+
+	ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, msm_dp_ctrl);
+
+	pixel_rate = pixel_rate_orig = ctrl->panel->msm_dp_mode.drm_mode.clock;
+
+	if (msm_dp_ctrl->wide_bus_en || ctrl->panel->msm_dp_mode.out_fmt_is_yuv_420)
+		pixel_rate >>= 1;
+
+	drm_dbg_dp(ctrl->drm_dev, "pixel_rate=%lu\n", pixel_rate);
+
 	ret = clk_set_rate(ctrl->pixel_clk, pixel_rate * 1000);
 	if (ret) {
 		DRM_ERROR("Failed to set pixel clock rate. ret=%d\n", ret);
@@ -2031,12 +2052,6 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train
 		ctrl->stream_clks_on = true;
 	}
 
-	if (force_link_train || !msm_dp_ctrl_channel_eq_ok(ctrl))
-		msm_dp_ctrl_link_retrain(ctrl);
-
-	/* stop txing train pattern to end link training */
-	msm_dp_ctrl_clear_training_pattern(ctrl, DP_PHY_DPRX);
-
 	/*
 	 * Set up transfer unit values and set controller state to send
 	 * video.
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
index b7abfedbf5749c25877a0b8ba3af3d8ed4b23d67..42745c912adbad7221c78f5cecefa730bfda1e75 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
@@ -18,7 +18,8 @@ struct msm_dp_ctrl {
 struct phy;
 
 int msm_dp_ctrl_on_link(struct msm_dp_ctrl *msm_dp_ctrl);
-int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train);
+int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl);
+int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *dp_ctrl, bool force_link_train);
 void msm_dp_ctrl_off_link_stream(struct msm_dp_ctrl *msm_dp_ctrl);
 void msm_dp_ctrl_off_link(struct msm_dp_ctrl *msm_dp_ctrl);
 void msm_dp_ctrl_off(struct msm_dp_ctrl *msm_dp_ctrl);
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 9d2db9cbd2552470a36a63f70f517c35436f7280..5ac5dcf35b789f2bda052a2c17aae20aa48d8e18 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -831,7 +831,37 @@ static int msm_dp_display_set_mode(struct msm_dp *msm_dp_display,
 	return 0;
 }
 
-static int msm_dp_display_enable(struct msm_dp_display_private *dp, bool force_link_train)
+static int msm_dp_display_prepare(struct msm_dp_display_private *dp)
+{
+	int rc = 0;
+	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
+	bool force_link_train = false;
+
+	drm_dbg_dp(dp->drm_dev, "sink_count=%d\n", dp->link->sink_count);
+	if (msm_dp_display->prepared) {
+		drm_dbg_dp(dp->drm_dev, "Link already setup, return\n");
+		return 0;
+	}
+
+	rc = pm_runtime_resume_and_get(&msm_dp_display->pdev->dev);
+	if (rc) {
+		DRM_ERROR("failed to pm_runtime_resume\n");
+		return rc;
+	}
+
+	if (dp->hpd_state == ST_CONNECTED && !msm_dp_display->power_on) {
+		msm_dp_display_host_phy_init(dp);
+		force_link_train = true;
+	}
+
+	rc = msm_dp_ctrl_prepare_stream_on(dp->ctrl, force_link_train);
+	if (!rc)
+		msm_dp_display->prepared = true;
+
+	return rc;
+}
+
+static int msm_dp_display_enable(struct msm_dp_display_private *dp)
 {
 	int rc = 0;
 	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
@@ -842,7 +872,7 @@ static int msm_dp_display_enable(struct msm_dp_display_private *dp, bool force_l
 		return 0;
 	}
 
-	rc = msm_dp_ctrl_on_stream(dp->ctrl, force_link_train);
+	rc = msm_dp_ctrl_on_stream(dp->ctrl);
 	if (!rc)
 		msm_dp_display->power_on = true;
 
@@ -872,13 +902,10 @@ static int msm_dp_display_post_enable(struct msm_dp *msm_dp_display)
 	return 0;
 }
 
-static int msm_dp_display_disable(struct msm_dp_display_private *dp)
+static void msm_dp_display_audio_notify_disable(struct msm_dp_display_private *dp)
 {
 	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
 
-	if (!msm_dp_display->power_on)
-		return 0;
-
 	/* wait only if audio was enabled */
 	if (msm_dp_display->audio_enabled) {
 		/* signal the disconnect event */
@@ -889,6 +916,14 @@ static int msm_dp_display_disable(struct msm_dp_display_private *dp)
 	}
 
 	msm_dp_display->audio_enabled = false;
+}
+
+static int msm_dp_display_disable(struct msm_dp_display_private *dp)
+{
+	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
+
+	if (!msm_dp_display->power_on)
+		return 0;
 
 	if (dp->link->sink_count == 0) {
 		/*
@@ -1506,9 +1541,8 @@ void msm_dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
 	struct msm_dp_bridge *msm_dp_bridge = to_dp_bridge(drm_bridge);
 	struct msm_dp *dp = msm_dp_bridge->msm_dp_display;
 	int rc = 0;
+
 	struct msm_dp_display_private *msm_dp_display;
-	u32 hpd_state;
-	bool force_link_train = false;
 
 	msm_dp_display = container_of(dp, struct msm_dp_display_private, msm_dp_display);
 
@@ -1516,29 +1550,23 @@ void msm_dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
 		msm_dp_hpd_plug_handle(msm_dp_display, 0);
 
 	mutex_lock(&msm_dp_display->event_mutex);
-	if (pm_runtime_resume_and_get(&dp->pdev->dev)) {
-		DRM_ERROR("failed to pm_runtime_resume\n");
-		mutex_unlock(&msm_dp_display->event_mutex);
-		return;
-	}
 
-	hpd_state = msm_dp_display->hpd_state;
-	if (hpd_state == ST_DISCONNECT_PENDING) {
+	rc = msm_dp_display_prepare(msm_dp_display);
+	if (rc) {
+		DRM_ERROR("DP display prepare failed, rc=%d\n", rc);
 		mutex_unlock(&msm_dp_display->event_mutex);
 		return;
 	}
 
-	if (hpd_state == ST_CONNECTED && !dp->power_on) {
-		msm_dp_display_host_phy_init(msm_dp_display);
-		force_link_train = true;
-	}
-
-	msm_dp_display_enable(msm_dp_display, force_link_train);
-
-	rc = msm_dp_display_post_enable(dp);
-	if (rc) {
-		DRM_ERROR("DP display post enable failed, rc=%d\n", rc);
-		msm_dp_display_disable(msm_dp_display);
+	if (dp->prepared) {
+		rc = msm_dp_display_enable(msm_dp_display);
+		if (rc)
+			DRM_ERROR("DP display enable failed, rc=%d\n", rc);
+		rc = msm_dp_display_post_enable(dp);
+		if (rc) {
+			DRM_ERROR("DP display post enable failed, rc=%d\n", rc);
+			msm_dp_display_disable(msm_dp_display);
+		}
 	}
 
 	/* completed connection */
@@ -1560,6 +1588,20 @@ void msm_dp_bridge_atomic_disable(struct drm_bridge *drm_bridge,
 	msm_dp_ctrl_push_idle(msm_dp_display->ctrl);
 }
 
+static void msm_dp_display_unprepare(struct msm_dp_display_private *dp)
+{
+	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
+
+	if (!msm_dp_display->prepared) {
+		drm_dbg_dp(dp->drm_dev, "Link already setup, return\n");
+		return;
+	}
+
+	pm_runtime_put_sync(&msm_dp_display->pdev->dev);
+
+	msm_dp_display->prepared = false;
+}
+
 void msm_dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
 				       struct drm_atomic_state *state)
 {
@@ -1580,6 +1622,8 @@ void msm_dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
 		drm_dbg_dp(dp->drm_dev, "type=%d wrong hpd_state=%d\n",
 			   dp->connector_type, hpd_state);
 
+	msm_dp_display_audio_notify_disable(msm_dp_display);
+
 	msm_dp_display_disable(msm_dp_display);
 
 	hpd_state =  msm_dp_display->hpd_state;
@@ -1588,9 +1632,10 @@ void msm_dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
 		msm_dp_display->hpd_state = ST_DISCONNECTED;
 	}
 
+	msm_dp_display_unprepare(msm_dp_display);
+
 	drm_dbg_dp(dp->drm_dev, "type=%d Done\n", dp->connector_type);
 
-	pm_runtime_put_sync(&dp->pdev->dev);
 	mutex_unlock(&msm_dp_display->event_mutex);
 }
 
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
index cc6e2cab36e9c0b1527ff292e547cbb4d69fd95c..2394840e9f28e136705004c3e6af93fbe13c33c5 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -19,6 +19,7 @@ struct msm_dp {
 	bool link_ready;
 	bool audio_enabled;
 	bool power_on;
+	bool prepared;
 	unsigned int connector_type;
 	bool is_edp;
 	bool internal_hpd;

-- 
2.34.1



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