Bind FBO before timer query on Mali GL driver.

glBeginQuery(GL_TIME_ELAPSED/GL_TIMESTAMP) on Mali implementation
assumes a complete FrameBuffer. Without it glGetQueryObject will return
a meaningless value, causing some applications to misbehave.

This workaround caches and binds a default FBO in this case.

Bug: chromium:1356053,b/269068358
Change-Id: I756ded948c2c5aada744f9dd428ad77c37a009c6
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4359032
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Kramer Ge <fangzhoug@chromium.org>

include/platform/FeaturesGL_autogen.h

@@ -474,6 +474,12 @@ struct FeaturesGL : FeatureSetBase
         &members,
     };
 
+    FeatureInfo bindFramebufferForTimerQueries = {
+        "bindFramebufferForTimerQueries", FeatureCategory::OpenGLWorkarounds,
+        "Some drivers require a non-zero framebuffer when beginQuery for TimeElapsed or"
+        "Timestampis called.",
+        &members, "https://crbug.com/1356053"};
+
     FeatureInfo supportsFragmentShaderInterlockNV = {
         "supportsFragmentShaderInterlockNV", FeatureCategory::OpenGLFeatures,
         "Backend GL context supports NV_fragment_shader_interlock extension", &members,

include/platform/gl_features.json

@@ -651,6 +651,15 @@
                 "Some drivers ignore GL_CLIP_DISTANCEi_EXT state."
             ]
         },
+        {
+            "name": "bind_framebuffer_for_timer_queries",
+            "category": "Workarounds",
+            "description": [
+                "Some drivers require a non-zero framebuffer when beginQuery for TimeElapsed or",
+                "Timestampis called."
+            ],
+            "issue": "https://crbug.com/1356053"
+        },
         {
             "name": "supports_fragment_shader_interlock_NV",
             "category": "Features",

scripts/code_generation_hashes/ANGLE_features.json

@@ -2,7 +2,7 @@
   "include/platform/FeaturesD3D_autogen.h":
     "bdce5cac5c70e04fd39e9cf8c6969292",
   "include/platform/FeaturesGL_autogen.h":
-    "38325ab28fca006d06f46d1ad4ad2d63",
+    "331b1660b3982f6540e362764df26021",
   "include/platform/FeaturesMtl_autogen.h":
     "d67e2035dabd6e495737da385d5dbe94",
   "include/platform/FeaturesVk_autogen.h":
@@ -16,13 +16,13 @@
   "include/platform/gen_features.py":
     "062989f7a8f3ff3b383f98fc8908dc33",
   "include/platform/gl_features.json":
-    "83005189979f62258c7799ec6a6a7572",
+    "cef92e7ede4c824b8bae37123401d354",
   "include/platform/mtl_features.json":
     "cd4de616ed3d18620f8c5b16cb076e66",
   "include/platform/vk_features.json":
     "f871458b67decd588bcfed4b0381bdcb",
   "util/angle_features_autogen.cpp":
-    "2eac5da5a58249c9ad201c26666a0ff7",
+    "99892e8229c4ff449d5497711b5442a8",
   "util/angle_features_autogen.h":
-    "3da81e7b0093659f06fc1cc0137ed977"
+    "e037ccc8832726feecb9e9c098fce32f"
 }

src/libANGLE/renderer/gl/StateManagerGL.cpp

@@ -102,6 +102,7 @@ StateManagerGL::StateManagerGL(const FunctionsGL *functions,
       mPackSkipPixels(0),
       mFramebuffers(angle::FramebufferBindingSingletonMax, 0),
       mRenderbuffer(0),
+      mPlaceholderFbo(0),
       mScissorTestEnabled(false),
       mScissor(0, 0, 0, 0),
       mViewport(0, 0, 0, 0),
@@ -215,6 +216,10 @@ StateManagerGL::StateManagerGL(const FunctionsGL *functions,
 
 StateManagerGL::~StateManagerGL()
 {
+    if (mPlaceholderFbo != 0)
+    {
+        deleteFramebuffer(mPlaceholderFbo);
+    }
     if (mDefaultVAO != 0)
     {
         mFunctions->deleteVertexArrays(1, &mDefaultVAO);
@@ -759,6 +764,17 @@ void StateManagerGL::beginQuery(gl::QueryType type, QueryGL *queryObject, GLuint
     ASSERT(mQueries[type] == nullptr);
     ASSERT(queryId != 0);
 
+    if (mFeatures.bindFramebufferForTimerQueries.enabled &&
+        mFramebuffers[angle::FramebufferBindingDraw] == 0 &&
+        (type == gl::QueryType::TimeElapsed || type == gl::QueryType::Timestamp))
+    {
+        if (!mPlaceholderFbo)
+        {
+            mFunctions->genFramebuffers(1, &mPlaceholderFbo);
+        }
+        bindFramebuffer(GL_FRAMEBUFFER, mPlaceholderFbo);
+    }
+
     mQueries[type] = queryObject;
     mFunctions->beginQuery(ToGLenum(type), queryId);
 }

src/libANGLE/renderer/gl/StateManagerGL.h

@@ -454,6 +454,7 @@ class StateManagerGL final : angle::NonCopyable
     // TODO(jmadill): Convert to std::array when available
     std::vector<GLenum> mFramebuffers;
     GLuint mRenderbuffer;
+    GLuint mPlaceholderFbo;
 
     bool mScissorTestEnabled;
     gl::Rectangle mScissor;

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -136,6 +136,13 @@ bool IsAdreno5xx(const FunctionsGL *functions)
     return number != 0 && number >= 500 && number < 600;
 }
 
+bool IsMali(const FunctionsGL *functions)
+{
+    constexpr char Mali[]        = "Mali";
+    const char *nativeGLRenderer = GetString(functions, GL_RENDERER);
+    return angle::BeginsWith(nativeGLRenderer, Mali);
+}
+
 bool IsMaliT8xxOrOlder(const FunctionsGL *functions)
 {
     int number = getMaliTNumber(functions);
@@ -2513,6 +2520,9 @@ void InitializeFeatures(const FunctionsGL *functions, angle::FeaturesGL *feature
     // EXT_shader_pixel_local_storage
     ANGLE_FEATURE_CONDITION(features, supportsShaderPixelLocalStorageEXT,
                             functions->hasGLESExtension("GL_EXT_shader_pixel_local_storage"));
+
+    // https://crbug.com/1356053
+    ANGLE_FEATURE_CONDITION(features, bindFramebufferForTimerQueries, IsMali(functions));
 }
 
 void InitializeFrontendFeatures(const FunctionsGL *functions, angle::FrontendFeatures *features)

util/angle_features_autogen.cpp

@@ -43,6 +43,7 @@ constexpr PackedEnumMap<Feature, const char *> kFeatureNames = {{
     {Feature::AsyncCommandQueue, "asyncCommandQueue"},
     {Feature::Avoid1BitAlphaTextureFormats, "avoid1BitAlphaTextureFormats"},
     {Feature::AvoidStencilTextureSwizzle, "avoidStencilTextureSwizzle"},
+    {Feature::BindFramebufferForTimerQueries, "bindFramebufferForTimerQueries"},
     {Feature::BindTransformFeedbackBufferBeforeBindBufferRange,
      "bindTransformFeedbackBufferBeforeBindBufferRange"},
     {Feature::BorderColorSrgb, "borderColorSrgb"},

util/angle_features_autogen.h

@@ -42,6 +42,7 @@ enum class Feature
     AsyncCommandQueue,
     Avoid1BitAlphaTextureFormats,
     AvoidStencilTextureSwizzle,
+    BindFramebufferForTimerQueries,
     BindTransformFeedbackBufferBeforeBindBufferRange,
     BorderColorSrgb,
     BottomLeftOriginPresentRegionRectangles,