FAILED: patch "[PATCH] drm/amd/display: Fix fast updates on DCE 8.1" failed to apply to 6.18-stable tree

The patch below does not apply to the 6.18-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]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 687d31ea9ac76b299817060fa1e5582d6c752ae0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026100549-unselfish-oven-e619@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

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

From 687d31ea9ac76b299817060fa1e5582d6c752ae0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timur=20Krist=C3=B3f?= <[email protected]>
Date: Wed, 23 Sep 2026 14:20:32 +0200
Subject: [PATCH] drm/amd/display: Fix fast updates on DCE 8.1
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

DCE8 should use legacy fast updates.
This was already set for DCE 8.0 and 8.3, but it seems that DCE 8.1 (found in Kaveri chips) was forgotten.

This fix should be backported to all kernel versions that have "Refactor fast update to use new HWSS build sequence", but this patch won't apply cleanly to older kernels due to another refactor in "Remove dc param from check_update".

index 26820d35478a..2f4de697ec4b 100644
@@ -1148,6 +1148,8 @@ static bool dce81_construct(
 	dc->caps.max_cursor_size = 128;
 	dc->caps.min_horizontal_blanking_period = 80;
 	dc->caps.is_apu = true;
+	dc->debug = debug_defaults;
+	dc->check_config = config_defaults;
 
 	/*************************************************
 	 *  Create resources                             *

From: Timur Kristóf <[email protected]>

[ Upstream commit 687d31ea9ac76b299817060fa1e5582d6c752ae0 ]

DCE8 should use legacy fast updates.
This was already set for DCE 8.0 and 8.3, but it seems that DCE 8.1 (found in Kaveri chips) was forgotten.

This fix should be backported to all kernel versions that have "Refactor fast update to use new HWSS build sequence", but this patch won't apply cleanly to older kernels due to another refactor in "Remove dc param from check_update".

---
 drivers/gpu/drm/amd/display/dc/resource/dce80/dce80_resource.c | 1 +
 1 file changed, 1 insertion(+)

index b645c0c8ec3c5..9874d2cb632ce 100644
@@ -1121,6 +1121,7 @@ static bool dce81_construct(
 	dc->caps.max_cursor_size = 128;
 	dc->caps.min_horizontal_blanking_period = 80;
 	dc->caps.is_apu = true;
+	dc->debug = debug_defaults;
 
 	/*************************************************
 	 *  Create resources                             *

2.53.0