From: jsg <jsg@openbsd.org>
Date: Fri, 28 Jul 2023 07:05:07 +0000 (+0000)
Subject: drm/amd/display: fix linux dp link lost handled only one time
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=765f8faca8643cf51c40781068fffd326a9be67b;p=openbsd

drm/amd/display: fix linux dp link lost handled only one time

From Hersen Wu
78ea2ed76ce94f090d2a9c36b1b58f79ce3b93b8 in linux-6.1.y/6.1.42
e322843e5e33e72ff218d661f3d15ff9c9f2f1b5 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 87b0d88e6c9..b68f8778dfe 100644
--- a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1348,10 +1348,28 @@ static void dm_handle_hpd_rx_offload_work(struct work_struct *work)
 	} else if ((dc_link->connector_signal != SIGNAL_TYPE_EDP) &&
 			hpd_rx_irq_check_link_loss_status(dc_link, &offload_work->data) &&
 			dc_link_dp_allow_hpd_rx_irq(dc_link)) {
-		dc_link_dp_handle_link_loss(dc_link);
+		/* offload_work->data is from handle_hpd_rx_irq->
+		 * schedule_hpd_rx_offload_work.this is defer handle
+		 * for hpd short pulse. upon here, link status may be
+		 * changed, need get latest link status from dpcd
+		 * registers. if link status is good, skip run link
+		 * training again.
+		 */
+		union hpd_irq_data irq_data;
+
+		memset(&irq_data, 0, sizeof(irq_data));
+
+		/* before dc_link_dp_handle_link_loss, allow new link lost handle
+		 * request be added to work queue if link lost at end of dc_link_
+		 * dp_handle_link_loss
+		 */
 		spin_lock_irqsave(&offload_work->offload_wq->offload_lock, flags);
 		offload_work->offload_wq->is_handling_link_loss = false;
 		spin_unlock_irqrestore(&offload_work->offload_wq->offload_lock, flags);
+
+		if ((read_hpd_rx_irq_data(dc_link, &irq_data) == DC_OK) &&
+			hpd_rx_irq_check_link_loss_status(dc_link, &irq_data))
+			dc_link_dp_handle_link_loss(dc_link);
 	}
 	mutex_unlock(&adev->dm.dc_lock);
 
@@ -3326,7 +3344,7 @@ static void handle_hpd_rx_irq(void *param)
 	union hpd_irq_data hpd_irq_data;
 	bool link_loss = false;
 	bool has_left_work = false;
-	int idx = aconnector->base.index;
+	int idx = dc_link->link_index;
 	struct hpd_rx_irq_offload_work_queue *offload_wq = &adev->dm.hpd_rx_offload_wq[idx];
 
 	memset(&hpd_irq_data, 0, sizeof(hpd_irq_data));
@@ -3468,7 +3486,7 @@ static void register_hpd_handlers(struct amdgpu_device *adev)
 					(void *) aconnector);
 
 			if (adev->dm.hpd_rx_offload_wq)
-				adev->dm.hpd_rx_offload_wq[connector->index].aconnector =
+				adev->dm.hpd_rx_offload_wq[dc_link->link_index].aconnector =
 					aconnector;
 		}
 	}
diff --git a/sys/dev/pci/drm/amd/display/dc/core/dc_link_dp.c b/sys/dev/pci/drm/amd/display/dc/core/dc_link_dp.c
index 4aa4409da72..55ff9d95a1a 100644
--- a/sys/dev/pci/drm/amd/display/dc/core/dc_link_dp.c
+++ b/sys/dev/pci/drm/amd/display/dc/core/dc_link_dp.c
@@ -3115,7 +3115,7 @@ struct dc_link_settings dp_get_max_link_cap(struct dc_link *link)
 	return max_link_cap;
 }
 
-static enum dc_status read_hpd_rx_irq_data(
+enum dc_status read_hpd_rx_irq_data(
 	struct dc_link *link,
 	union hpd_irq_data *irq_data)
 {
diff --git a/sys/dev/pci/drm/amd/display/dc/inc/dc_link_dp.h b/sys/dev/pci/drm/amd/display/dc/inc/dc_link_dp.h
index dab08ad7852..197df396731 100644
--- a/sys/dev/pci/drm/amd/display/dc/inc/dc_link_dp.h
+++ b/sys/dev/pci/drm/amd/display/dc/inc/dc_link_dp.h
@@ -82,6 +82,10 @@ bool perform_link_training_with_retries(
 	enum amd_signal_type signal,
 	bool do_fallback);
 
+enum dc_status read_hpd_rx_irq_data(
+	struct dc_link *link,
+	union hpd_irq_data *irq_data);
+
 bool hpd_rx_irq_check_link_loss_status(
 	struct dc_link *link,
 	union hpd_irq_data *hpd_irq_dpcd_data);