From: jsg <jsg@openbsd.org>
Date: Sat, 15 Jun 2024 04:01:36 +0000 (+0000)
Subject: drm/bridge: Fix improper bridge init order with pre_enable_prev_first
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=625d3866dd3252249a62ba037b7a9ebde096e993;p=openbsd

drm/bridge: Fix improper bridge init order with pre_enable_prev_first

From Jagan Teki
45755ef11f0337110105d4a6a2cd6bdc278dffa0 in linux-6.6.y/6.6.33
e18aeeda0b6905c333df5a0566b99f5c84426098 in mainline linux
---

diff --git a/sys/dev/pci/drm/drm_bridge.c b/sys/dev/pci/drm/drm_bridge.c
index ce490620986..e02c2923e91 100644
--- a/sys/dev/pci/drm/drm_bridge.c
+++ b/sys/dev/pci/drm/drm_bridge.c
@@ -694,11 +694,17 @@ void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
 				 */
 				list_for_each_entry_from(next, &encoder->bridge_chain,
 							 chain_node) {
-					if (next->pre_enable_prev_first) {
+					if (!next->pre_enable_prev_first) {
 						next = list_prev_entry(next, chain_node);
 						limit = next;
 						break;
 					}
+
+					if (list_is_last(&next->chain_node,
+							 &encoder->bridge_chain)) {
+						limit = next;
+						break;
+					}
 				}
 
 				/* Call these bridges in reverse order */
@@ -781,7 +787,7 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
 					/* Found first bridge that does NOT
 					 * request prev to be enabled first
 					 */
-					limit = list_prev_entry(next, chain_node);
+					limit = next;
 					break;
 				}
 			}