From 921d48815f191d63b93aeb9c9921ba6dd95b054e Mon Sep 17 00:00:00 2001
From: Brandon Jones <[email protected]>
Date: Thu, 20 Aug 2026 13:54:51 -0700
Subject: [PATCH] Insert flush before generateMipmap on IMG

Adds a feature which forces a flush before generating a mipmap,
which avoids a bad state in the IMG driver if the texture's base
level is still bound to an active FBO.

Fixed: chromium:549350408
Change-Id: Id69684690a0fb04a45e0fca7d912bac68f82052c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/8265721
Commit-Queue: Kenneth Russell <[email protected]>
Reviewed-by: Geoff Lang <[email protected]>
Reviewed-by: Kenneth Russell <[email protected]>
---

diff --git a/include/platform/autogen/FeaturesGL_autogen.h b/include/platform/autogen/FeaturesGL_autogen.h
index 58c6372..487cfbe 100644
--- a/include/platform/autogen/FeaturesGL_autogen.h
+++ b/include/platform/autogen/FeaturesGL_autogen.h
@@ -734,6 +734,12 @@
         &members,
     };
 
+    FeatureInfo flushBeforeGenerateMipmap = {
+        "flushBeforeGenerateMipmap",
+        FeatureCategory::OpenGLWorkarounds,
+        &members,
+    };
+
     FeatureInfo splitLevel0PboFullSubImage2D = {
         "splitLevel0PboFullSubImage2D",
         FeatureCategory::OpenGLWorkarounds,
diff --git a/include/platform/gl_features.json b/include/platform/gl_features.json
index 18a3244..7d9f4bb 100644
--- a/include/platform/gl_features.json
+++ b/include/platform/gl_features.json
@@ -963,6 +963,14 @@
             "issue": "http://crbug.com/475877320"
         },
         {
+            "name": "flush_before_generate_mipmap",
+            "category": "Workarounds",
+            "description": [
+                "Force a flush before calling generateMipmap to work around driver bugs."
+            ],
+            "issue": "http://crbug.com/549350408"
+        },
+        {
             "name": "split_level_0_pbo_full_sub_image_2D",
             "category": "Workarounds",
             "description": [
diff --git a/src/libANGLE/renderer/gl/TextureGL.cpp b/src/libANGLE/renderer/gl/TextureGL.cpp
index 63fc458..52c5e88 100644
--- a/src/libANGLE/renderer/gl/TextureGL.cpp
+++ b/src/libANGLE/renderer/gl/TextureGL.cpp
@@ -1622,6 +1622,13 @@
     StateManagerGL *stateManager      = GetStateManagerGL(context);
     const angle::FeaturesGL &features = GetFeaturesGL(context);
 
+    if (features.flushBeforeGenerateMipmap.enabled)
+    {
+        // Force a flush before generating the mipmap, which avoids a bad state in the IMG driver if
+        // the texture's base level is still bound to an active FBO.
+        ANGLE_GL_TRY(context, functions->flush());
+    }
+
     stateManager->bindTexture(getType(), mTextureID);
 
     bool recreateMipmapLevelsBeforeGenerate =
diff --git a/src/libANGLE/renderer/gl/renderergl_utils.cpp b/src/libANGLE/renderer/gl/renderergl_utils.cpp
index daded80..2190fd8 100644
--- a/src/libANGLE/renderer/gl/renderergl_utils.cpp
+++ b/src/libANGLE/renderer/gl/renderergl_utils.cpp
@@ -2748,6 +2748,10 @@
     // Disable EXT_clear_texture entirely on IMG as a speculative fix for driver crashes.
     ANGLE_FEATURE_CONDITION(features, disableClearTexture, IsPowerVR(vendor));
 
+    // Forces a flush before generating a mipmap, which avoids a bad state in the IMG driver if
+    // the texture's base level is still bound to an active FBO.
+    ANGLE_FEATURE_CONDITION(features, flushBeforeGenerateMipmap, IsPowerVR(vendor));
+
     // IMG GL drivers crash while compiling shaders with more than the limit of uniform blocks.
     ANGLE_FEATURE_CONDITION(features, validateMaxPerStageUniformBlocksAtCompileTime,
                             IsPowerVR(vendor));
diff --git a/util/autogen/angle_features_autogen.cpp b/util/autogen/angle_features_autogen.cpp
index 2d2096b..5f52c9e 100644
--- a/util/autogen/angle_features_autogen.cpp
+++ b/util/autogen/angle_features_autogen.cpp
@@ -189,6 +189,7 @@
     {Feature::FlushAfterEndingTransformFeedback, "flushAfterEndingTransformFeedback"},
     {Feature::FlushAfterStreamVertexData, "flushAfterStreamVertexData"},
     {Feature::FlushBeforeDeleteTextureIfCopiedTo, "flushBeforeDeleteTextureIfCopiedTo"},
+    {Feature::FlushBeforeGenerateMipmap, "flushBeforeGenerateMipmap"},
     {Feature::FlushOnFramebufferChange, "flushOnFramebufferChange"},
     {Feature::FlushQueriesBeforeDeletingOrUnbindingFbo, "flushQueriesBeforeDeletingOrUnbindingFbo"},
     {Feature::ForceAtomicValueResolution, "forceAtomicValueResolution"},
diff --git a/util/autogen/angle_features_autogen.h b/util/autogen/angle_features_autogen.h
index 0d329ff..99b3126 100644
--- a/util/autogen/angle_features_autogen.h
+++ b/util/autogen/angle_features_autogen.h
@@ -189,6 +189,7 @@
     FlushAfterEndingTransformFeedback,
     FlushAfterStreamVertexData,
     FlushBeforeDeleteTextureIfCopiedTo,
+    FlushBeforeGenerateMipmap,
     FlushOnFramebufferChange,
     FlushQueriesBeforeDeletingOrUnbindingFbo,
     ForceAtomicValueResolution,