1 files changed, 154 insertions, 12 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 0d03e324d5b9..2a7a491a62e0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -551,13 +551,13 @@ static void schedule_dc_vmin_vmax(struct amdgpu_device *adev,
 	struct dc_stream_state *stream,
 	struct dc_crtc_timing_adjust *adjust)
 {
-	struct vupdate_offload_work *offload_work = kzalloc(sizeof(*offload_work), GFP_KERNEL);
+	struct vupdate_offload_work *offload_work = kzalloc(sizeof(*offload_work), GFP_NOWAIT);
 	if (!offload_work) {
 		drm_dbg_driver(adev_to_drm(adev), "Failed to allocate vupdate_offload_work\n");
 		return;
 	}
 
-	struct dc_crtc_timing_adjust *adjust_copy = kzalloc(sizeof(*adjust_copy), GFP_KERNEL);
+	struct dc_crtc_timing_adjust *adjust_copy = kzalloc(sizeof(*adjust_copy), GFP_NOWAIT);
 	if (!adjust_copy) {
 		drm_dbg_driver(adev_to_drm(adev), "Failed to allocate adjust_copy\n");
 		kfree(offload_work);
@@ -2085,8 +2085,6 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 
 	dc_hardware_init(adev->dm.dc);
 
-	adev->dm.restore_backlight = true;
-
 	adev->dm.hpd_rx_offload_wq = hpd_rx_irq_create_workqueue(adev);
 	if (!adev->dm.hpd_rx_offload_wq) {
 		drm_err(adev_to_drm(adev), "failed to create hpd rx offload workqueue.\n");
@@ -3442,7 +3440,6 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
 		dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D0);
 
 		dc_resume(dm->dc);
-		adev->dm.restore_backlight = true;
 
 		amdgpu_dm_irq_resume_early(adev);
 
@@ -3566,6 +3563,7 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
 	/* Do mst topology probing after resuming cached state*/
 	drm_connector_list_iter_begin(ddev, &iter);
 	drm_for_each_connector_iter(connector, &iter) {
+		bool init = false;
 
 		if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
 			continue;
@@ -3575,7 +3573,14 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
 		    aconnector->mst_root)
 			continue;
 
-		drm_dp_mst_topology_queue_probe(&aconnector->mst_mgr);
+		scoped_guard(mutex, &aconnector->mst_mgr.lock) {
+			init = !aconnector->mst_mgr.mst_primary;
+		}
+		if (init)
+			dm_helpers_dp_mst_start_top_mgr(aconnector->dc_link->ctx,
+				aconnector->dc_link, false);
+		else
+			drm_dp_mst_topology_queue_probe(&aconnector->mst_mgr);
 	}
 	drm_connector_list_iter_end(&iter);
 
@@ -3854,6 +3859,97 @@ void amdgpu_dm_update_connector_after_detect(
 	update_subconnector_property(aconnector);
 }
 
+static bool are_sinks_equal(const struct dc_sink *sink1, const struct dc_sink *sink2)
+{
+	if (!sink1 || !sink2)
+		return false;
+	if (sink1->sink_signal != sink2->sink_signal)
+		return false;
+
+	if (sink1->dc_edid.length != sink2->dc_edid.length)
+		return false;
+
+	if (memcmp(sink1->dc_edid.raw_edid, sink2->dc_edid.raw_edid,
+		   sink1->dc_edid.length) != 0)
+		return false;
+	return true;
+}
+
+
+/**
+ * DOC: hdmi_hpd_debounce_work
+ *
+ * HDMI HPD debounce delay in milliseconds. When an HDMI display toggles HPD
+ * (such as during power save transitions), this delay determines how long to
+ * wait before processing the HPD event. This allows distinguishing between a
+ * physical unplug (>hdmi_hpd_debounce_delay)
+ * and a spontaneous RX HPD toggle (<hdmi_hpd_debounce_delay).
+ *
+ * If the toggle is less than this delay, the driver compares sink capabilities
+ * and permits a hotplug event if they changed.
+ *
+ * The default value of 1500ms was chosen based on experimental testing with
+ * various monitors that exhibit spontaneous HPD toggling behavior.
+ */
+static void hdmi_hpd_debounce_work(struct work_struct *work)
+{
+	struct amdgpu_dm_connector *aconnector =
+		container_of(to_delayed_work(work), struct amdgpu_dm_connector,
+			     hdmi_hpd_debounce_work);
+	struct drm_connector *connector = &aconnector->base;
+	struct drm_device *dev = connector->dev;
+	struct amdgpu_device *adev = drm_to_adev(dev);
+	struct dc *dc = aconnector->dc_link->ctx->dc;
+	bool fake_reconnect = false;
+	bool reallow_idle = false;
+	bool ret = false;
+	guard(mutex)(&aconnector->hpd_lock);
+
+	/* Re-detect the display */
+	scoped_guard(mutex, &adev->dm.dc_lock) {
+		if (dc->caps.ips_support && dc->ctx->dmub_srv->idle_allowed) {
+			dc_allow_idle_optimizations(dc, false);
+			reallow_idle = true;
+		}
+		ret = dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD);
+	}
+
+	if (ret) {
+		/* Apply workaround delay for certain panels */
+		apply_delay_after_dpcd_poweroff(adev, aconnector->dc_sink);
+		/* Compare sinks to determine if this was a spontaneous HPD toggle */
+		if (are_sinks_equal(aconnector->dc_link->local_sink, aconnector->hdmi_prev_sink)) {
+			/*
+			* Sinks match - this was a spontaneous HDMI HPD toggle.
+			*/
+			drm_dbg_kms(dev, "HDMI HPD: Sink unchanged after debounce, internal re-enable\n");
+			fake_reconnect = true;
+		}
+
+		/* Update connector state */
+		amdgpu_dm_update_connector_after_detect(aconnector);
+
+		drm_modeset_lock_all(dev);
+		dm_restore_drm_connector_state(dev, connector);
+		drm_modeset_unlock_all(dev);
+
+		/* Only notify OS if sink actually changed */
+		if (!fake_reconnect && aconnector->base.force == DRM_FORCE_UNSPECIFIED)
+			drm_kms_helper_hotplug_event(dev);
+	}
+
+	/* Release the cached sink reference */
+	if (aconnector->hdmi_prev_sink) {
+		dc_sink_release(aconnector->hdmi_prev_sink);
+		aconnector->hdmi_prev_sink = NULL;
+	}
+
+	scoped_guard(mutex, &adev->dm.dc_lock) {
+		if (reallow_idle && dc->caps.ips_support)
+			dc_allow_idle_optimizations(dc, true);
+	}
+}
+
 static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector)
 {
 	struct drm_connector *connector = &aconnector->base;
@@ -3863,6 +3959,7 @@ static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector)
 	struct dm_connector_state *dm_con_state = to_dm_connector_state(connector->state);
 	struct dc *dc = aconnector->dc_link->ctx->dc;
 	bool ret = false;
+	bool debounce_required = false;
 
 	if (adev->dm.disable_hpd_irq)
 		return;
@@ -3885,6 +3982,14 @@ static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector)
 	if (!dc_link_detect_connection_type(aconnector->dc_link, &new_connection_type))
 		drm_err(adev_to_drm(adev), "KMS: Failed to detect connector\n");
 
+	/*
+	 * Check for HDMI disconnect with debounce enabled.
+	 */
+	debounce_required = (aconnector->hdmi_hpd_debounce_delay_ms > 0 &&
+			      dc_is_hdmi_signal(aconnector->dc_link->connector_signal) &&
+			      new_connection_type == dc_connection_none &&
+			      aconnector->dc_link->local_sink != NULL);
+
 	if (aconnector->base.force && new_connection_type == dc_connection_none) {
 		emulated_link_detect(aconnector->dc_link);
 
@@ -3894,7 +3999,34 @@ static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector)
 
 		if (aconnector->base.force == DRM_FORCE_UNSPECIFIED)
 			drm_kms_helper_connector_hotplug_event(connector);
+	} else if (debounce_required) {
+		/*
+		 * HDMI disconnect detected - schedule delayed work instead of
+		 * processing immediately. This allows us to coalesce spurious
+		 * HDMI signals from physical unplugs.
+		 */
+		drm_dbg_kms(dev, "HDMI HPD: Disconnect detected, scheduling debounce work (%u ms)\n",
+			    aconnector->hdmi_hpd_debounce_delay_ms);
+
+		/* Cache the current sink for later comparison */
+		if (aconnector->hdmi_prev_sink)
+			dc_sink_release(aconnector->hdmi_prev_sink);
+		aconnector->hdmi_prev_sink = aconnector->dc_link->local_sink;
+		if (aconnector->hdmi_prev_sink)
+			dc_sink_retain(aconnector->hdmi_prev_sink);
+
+		/* Schedule delayed detection. */
+		if (mod_delayed_work(system_wq,
+				 &aconnector->hdmi_hpd_debounce_work,
+				 msecs_to_jiffies(aconnector->hdmi_hpd_debounce_delay_ms)))
+			drm_dbg_kms(dev, "HDMI HPD: Re-scheduled debounce work\n");
+
 	} else {
+
+		/* If the aconnector->hdmi_hpd_debounce_work is scheduled, exit early */
+		if (delayed_work_pending(&aconnector->hdmi_hpd_debounce_work))
+			return;
+
 		scoped_guard(mutex, &adev->dm.dc_lock) {
 			dc_exit_ips_for_hw_access(dc);
 			ret = dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD);
@@ -7383,6 +7515,13 @@ static void amdgpu_dm_connector_destroy(struct drm_connector *connector)
 	if (aconnector->mst_mgr.dev)
 		drm_dp_mst_topology_mgr_destroy(&aconnector->mst_mgr);
 
+	/* Cancel and flush any pending HDMI HPD debounce work */
+	cancel_delayed_work_sync(&aconnector->hdmi_hpd_debounce_work);
+	if (aconnector->hdmi_prev_sink) {
+		dc_sink_release(aconnector->hdmi_prev_sink);
+		aconnector->hdmi_prev_sink = NULL;
+	}
+
 	if (aconnector->bl_idx != -1) {
 		backlight_device_unregister(dm->backlight_dev[aconnector->bl_idx]);
 		dm->backlight_dev[aconnector->bl_idx] = NULL;
@@ -8033,7 +8172,7 @@ static int dm_encoder_helper_atomic_check(struct drm_encoder *encoder,
 				       "mode %dx%d@%dHz is not native, enabling scaling\n",
 				       adjusted_mode->hdisplay, adjusted_mode->vdisplay,
 				       drm_mode_vrefresh(adjusted_mode));
-			dm_new_connector_state->scaling = RMX_FULL;
+			dm_new_connector_state->scaling = RMX_ASPECT;
 		}
 		return 0;
 	}
@@ -8544,6 +8683,10 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 	mutex_init(&aconnector->hpd_lock);
 	mutex_init(&aconnector->handle_mst_msg_ready);
 
+	aconnector->hdmi_hpd_debounce_delay_ms = AMDGPU_DM_HDMI_HPD_DEBOUNCE_MS;
+	INIT_DELAYED_WORK(&aconnector->hdmi_hpd_debounce_work, hdmi_hpd_debounce_work);
+	aconnector->hdmi_prev_sink = NULL;
+
 	/*
 	 * configure support HPD hot plug connector_>polled default value is 0
 	 * which means HPD hot plug not supported
@@ -9969,6 +10112,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 	bool mode_set_reset_required = false;
 	u32 i;
 	struct dc_commit_streams_params params = {dc_state->streams, dc_state->stream_count};
+	bool set_backlight_level = false;
 
 	/* Disable writeback */
 	for_each_old_connector_in_state(state, connector, old_con_state, i) {
@@ -10088,6 +10232,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 			acrtc->hw_mode = new_crtc_state->mode;
 			crtc->hwmode = new_crtc_state->mode;
 			mode_set_reset_required = true;
+			set_backlight_level = true;
 		} else if (modereset_required(new_crtc_state)) {
 			drm_dbg_atomic(dev,
 				       "Atomic commit: RESET. crtc id %d:[%p]\n",
@@ -10144,16 +10289,13 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 	 * to fix a flicker issue.
 	 * It will cause the dm->actual_brightness is not the current panel brightness
 	 * level. (the dm->brightness is the correct panel level)
-	 * So we set the backlight level with dm->brightness value after initial
-	 * set mode. Use restore_backlight flag to avoid setting backlight level
-	 * for every subsequent mode set.
+	 * So we set the backlight level with dm->brightness value after set mode
 	 */
-	if (dm->restore_backlight) {
+	if (set_backlight_level) {
 		for (i = 0; i < dm->num_of_edps; i++) {
 			if (dm->backlight_dev[i])
 				amdgpu_dm_backlight_set_level(dm, i, dm->brightness[i]);
 		}
-		dm->restore_backlight = false;
 	}
 }