5 files changed, 64 insertions, 27 deletions

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
index 31316fe1ea8d..0f3662d8737e 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
@@ -55,6 +55,7 @@ struct hibmc_dp {
 	struct drm_dp_aux aux;
 	struct hibmc_dp_cbar_cfg cfg;
 	u32 irq_status;
+	int phys_status;
 };
 
 int hibmc_dp_hw_init(struct hibmc_dp *dp);
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
index 5b9dedfbbdfc..2e9403b8bf3c 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
@@ -61,27 +61,38 @@ static int hibmc_dp_detect(struct drm_connector *connector,
 {
 	struct hibmc_dp *dp = to_hibmc_dp(connector);
 	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
-	int ret;
+	int ret = connector_status_disconnected;
 
 	if (dp->irq_status) {
-		if (dp_dev->hpd_status != HIBMC_HPD_IN)
-			return connector_status_disconnected;
+		if (dp_dev->hpd_status != HIBMC_HPD_IN) {
+			ret = connector_status_disconnected;
+			goto exit;
+		}
 	}
 
-	if (!hibmc_dp_get_dpcd(dp_dev))
-		return connector_status_disconnected;
+	if (!hibmc_dp_get_dpcd(dp_dev)) {
+		ret = connector_status_disconnected;
+		goto exit;
+	}
 
-	if (!dp_dev->is_branch)
-		return connector_status_connected;
+	if (!dp_dev->is_branch) {
+		ret = connector_status_connected;
+		goto exit;
+	}
 
 	if (drm_dp_read_sink_count_cap(connector, dp_dev->dpcd, &dp_dev->desc) &&
 	    dp_dev->downstream_ports[0] & DP_DS_PORT_HPD) {
 		ret = drm_dp_read_sink_count(dp_dev->aux);
-		if (ret > 0)
-			return connector_status_connected;
+		if (ret > 0) {
+			ret = connector_status_connected;
+			goto exit;
+		}
 	}
 
-	return connector_status_disconnected;
+exit:
+	dp->phys_status = ret;
+
+	return ret;
 }
 
 static int hibmc_dp_mode_valid(struct drm_connector *connector,
@@ -243,5 +254,7 @@ int hibmc_dp_init(struct hibmc_drm_private *priv)
 
 	connector->polled = DRM_CONNECTOR_POLL_HPD;
 
+	dp->phys_status = connector_status_disconnected;
+
 	return 0;
 }
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
index 289304500ab0..481e5e62c30b 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
@@ -24,6 +24,7 @@
 #include <drm/drm_managed.h>
 #include <drm/drm_module.h>
 #include <drm/drm_vblank.h>
+#include <drm/drm_probe_helper.h>
 
 #include "hibmc_drm_drv.h"
 #include "hibmc_drm_regs.h"
@@ -355,6 +356,8 @@ static int hibmc_load(struct drm_device *dev)
 	/* reset all the states of crtc/plane/encoder/connector */
 	drm_mode_config_reset(dev);
 
+	drmm_kms_helper_poll_init(dev);
+
 	return 0;
 
 err:
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
index ca8502e2760c..cd3a3fca1fe6 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
@@ -31,6 +31,7 @@ struct hibmc_vdac {
 	struct drm_connector connector;
 	struct i2c_adapter adapter;
 	struct i2c_algo_bit_data bit_data;
+	int phys_status;
 };
 
 struct hibmc_drm_private {
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
index 841e81f47b68..2fcfa3246fd1 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
@@ -24,28 +24,21 @@
 
 static int hibmc_connector_get_modes(struct drm_connector *connector)
 {
+	struct drm_mode_config *mode_config = &connector->dev->mode_config;
 	struct hibmc_vdac *vdac = to_hibmc_vdac(connector);
-	const struct drm_edid *drm_edid;
 	int count;
 
-	drm_edid = drm_edid_read_ddc(connector, &vdac->adapter);
-
-	drm_edid_connector_update(connector, drm_edid);
-
-	if (drm_edid) {
-		count = drm_edid_connector_add_modes(connector);
+	if (vdac->phys_status == connector_status_connected) {
+		count = drm_connector_helper_get_modes(connector);
+	} else {
+		drm_edid_connector_update(connector, NULL);
+		count = drm_add_modes_noedid(connector,
+					     mode_config->max_width,
+					     mode_config->max_height);
 		if (count)
-			goto out;
+			drm_set_preferred_mode(connector, 1024, 768);
 	}
 
-	count = drm_add_modes_noedid(connector,
-				     connector->dev->mode_config.max_width,
-				     connector->dev->mode_config.max_height);
-	drm_set_preferred_mode(connector, 1024, 768);
-
-out:
-	drm_edid_free(drm_edid);
-
 	return count;
 }
 
@@ -57,10 +50,34 @@ static void hibmc_connector_destroy(struct drm_connector *connector)
 	drm_connector_cleanup(connector);
 }
 
+static int hibmc_vdac_detect(struct drm_connector *connector,
+			     struct drm_modeset_acquire_ctx *ctx,
+			     bool force)
+{
+	struct hibmc_drm_private *priv = to_hibmc_drm_private(connector->dev);
+	int status = drm_connector_helper_detect_from_ddc(connector, ctx,
+							 force);
+	struct hibmc_vdac *vdac = to_hibmc_vdac(connector);
+
+	if (priv->dp.phys_status == connector_status_connected) {
+		vdac->phys_status = status;
+		return status;
+	}
+
+	if (status != vdac->phys_status)
+		++connector->epoch_counter;
+	vdac->phys_status = status;
+
+	/* When both the DP and VDAC physical status are disconnected,
+	 * the "connected" status is returned to support KVM display.
+	 */
+	return connector_status_connected;
+}
+
 static const struct drm_connector_helper_funcs
 	hibmc_connector_helper_funcs = {
 	.get_modes = hibmc_connector_get_modes,
-	.detect_ctx = drm_connector_helper_detect_from_ddc,
+	.detect_ctx = hibmc_vdac_detect,
 };
 
 static const struct drm_connector_funcs hibmc_connector_funcs = {
@@ -130,6 +147,8 @@ int hibmc_vdac_init(struct hibmc_drm_private *priv)
 
 	connector->polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
 
+	vdac->phys_status = connector_status_disconnected;
+
 	return 0;
 
 err: