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FAILED: patch "[PATCH] drm/amdgpu/mst: Stop ignoring error codes and deadlocking" failed to apply to 6.1-stable tree

PATCH [email protected] 1 participant 1 message Jan 4, 2023

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Stable branch DRM drivers Radeon and amdgpu DRM drivers AMD display core
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The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

7cce4cd628be ("drm/amdgpu/mst: Stop ignoring error codes and deadlocking")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7cce4cd628bee0d0caff7518c377cf8f599aa38f Mon Sep 17 00:00:00 2001
From: Lyude Paul <[email protected]>
Date: Mon, 14 Nov 2022 17:17:52 -0500
Subject: [PATCH] drm/amdgpu/mst: Stop ignoring error codes and deadlocking

It appears that amdgpu makes the mistake of completely ignoring the return values from the DP MST helpers, and instead just returns a simple true/false. In this case, it seems to have come back to bite us because as a result of simply returning false from compute_mst_dsc_configs_for_state(), amdgpu had no way of telling when a deadlock happened from these helpers. This could definitely result in some kernel splats.

V2:
* Address Wayne's comments (fix another bunch of spots where we weren't passing down return codes)

Signed-off-by Lyude Paul <[email protected]>
Fixes 8c20a1ed9b4f ("drm/amd/display: MST DSC compute fair share")
Cc Harry Wentland <[email protected]>
Cc <[email protected]> # v5.6+
Reviewed-by Wayne Lin <[email protected]>
Signed-off-by Alex Deucher <[email protected]>
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +10 -8
index 35fa88787dc1..ef4f788edabe 100644
@@ -6539,7 +6539,7 @@ static int dm_update_mst_vcpi_slots_for_dsc(struct drm_atomic_state *state,
 	struct drm_connector_state *new_con_state;
 	struct amdgpu_dm_connector *aconnector;
 	struct dm_connector_state *dm_conn_state;
-	int i, j;
+	int i, j, ret;
 	int vcpi, pbn_div, pbn, slot_num = 0;
 
 	for_each_new_connector_in_state(state, connector, new_con_state, i) {

@@ -6586,8 +6586,11 @@ static int dm_update_mst_vcpi_slots_for_dsc(struct drm_atomic_state *state,
 			dm_conn_state->pbn = pbn;
 			dm_conn_state->vcpi_slots = slot_num;
 
-			drm_dp_mst_atomic_enable_dsc(state, aconnector->port, dm_conn_state->pbn,
-						     false);
+			ret = drm_dp_mst_atomic_enable_dsc(state, aconnector->port,
+							   dm_conn_state->pbn, false);
+			if (ret < 0)
+				return ret;
+
 			continue;
 		}
 

@@ -9604,10 +9607,9 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	if (dc_resource_is_dsc_encoding_supported(dc)) {
-		if (!pre_validate_dsc(state, &dm_state, vars)) {
-			ret = -EINVAL;
+		ret = pre_validate_dsc(state, &dm_state, vars);
+		if (ret != 0)
 			goto fail;
-		}
 	}
 #endif
 

@@ -9702,9 +9704,9 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 		}
 
 #if defined(CONFIG_DRM_AMD_DC_DCN)
-		if (!compute_mst_dsc_configs_for_state(state, dm_state->context, vars)) {
+		ret = compute_mst_dsc_configs_for_state(state, dm_state->context, vars);
+		if (ret) {
 			DRM_DEBUG_DRIVER("compute_mst_dsc_configs_for_state() failed\n");
-			ret = -EINVAL;
 			goto fail;
 		}
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +131 -104

423 lines not on this page · raw message

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h +6 -6
index b92a7c5671aa..97fd70df531b 100644
@@ -53,15 +53,15 @@ struct dsc_mst_fairness_vars {
 	struct amdgpu_dm_connector *aconnector;
 };
 
-bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
-				       struct dc_state *dc_state,
-				       struct dsc_mst_fairness_vars *vars);
+int compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
+				      struct dc_state *dc_state,
+				      struct dsc_mst_fairness_vars *vars);
 
 bool needs_dsc_aux_workaround(struct dc_link *link);
 
-bool pre_validate_dsc(struct drm_atomic_state *state,
-		      struct dm_atomic_state **dm_state_ptr,
-		      struct dsc_mst_fairness_vars *vars);
+int pre_validate_dsc(struct drm_atomic_state *state,
+		     struct dm_atomic_state **dm_state_ptr,
+		     struct dsc_mst_fairness_vars *vars);
 
 enum dc_status dm_dp_mst_is_port_support_mode(
 	struct amdgpu_dm_connector *aconnector,