File 0001-backends-drm-work-around-amdgpu-applying-GAMMA_LUT-i.patch of Package kwin6

From 7d36003cb073ed2ad48b2743883db993106c347a Mon Sep 17 00:00:00 2001
From: Xaver Hugl <xaver.hugl@kde.org>
Date: Wed, 20 Aug 2025 23:12:58 +0200
Subject: [PATCH] backends/drm: work around amdgpu applying GAMMA_LUT in
 test-only commits

See https://gitlab.freedesktop.org/drm/amd/-/issues/4444 for details.
This does not cover up all the cases where the bug causes visible issues, but
it helps with the most annoying ones (at the cost of some performance during
brightness or color temperature animations).

For testing potential driver fixes, KWIN_DRM_DISABLE_AMD_GAMMA_WORKAROUND can
be set to 1 to disable this workaround.

CCBUG: 508350


(cherry picked from commit d2df32c9c664023bb6a1409dbaecbd3078dbaaec)

Co-authored-by: Xaver Hugl <xaver.hugl@kde.org>
---
 src/backends/drm/drm_colorop.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/backends/drm/drm_colorop.cpp b/src/backends/drm/drm_colorop.cpp
index 51ca1369fc..281c1e780f 100644
--- a/src/backends/drm/drm_colorop.cpp
+++ b/src/backends/drm/drm_colorop.cpp
@@ -9,7 +9,9 @@
 #include "drm_colorop.h"
 #include "drm_blob.h"
 #include "drm_commit.h"
+#include "drm_gpu.h"
 #include "drm_object.h"
+#include "utils/envvar.h"
 
 #include <ranges>
 
@@ -30,13 +32,15 @@ DrmAbstractColorOp *DrmAbstractColorOp::next() const
     return m_next;
 }
 
+static const auto s_disableAmdgpuWorkaround = environmentVariableBoolValue("KWIN_DRM_DISABLE_AMD_GAMMA_WORKAROUND");
+
 bool DrmAbstractColorOp::matchPipeline(DrmAtomicCommit *commit, const ColorPipeline &pipeline)
 {
     if (m_cachedPipeline && *m_cachedPipeline == pipeline) {
         commit->merge(m_cache.get());
         return true;
     }
-    if (pipeline.isIdentity()) {
+    if (pipeline.isIdentity() && s_disableAmdgpuWorkaround.value_or(!commit->gpu()->isAmdgpu())) {
         // Applying this config is very simple and cheap, so do it directly
         // and avoid invalidating the cache
         DrmAbstractColorOp *currentOp = this;
-- 
2.50.1