Bug 686735 - 1/2 - Implement no-gfx-driver-workarounds mode - r=joe,ajuma,jgilbert

Part 1: introduce the gfx.work-around-driver-bugs preference and handle most existing workarounds

content/canvas/src/WebGLContextGL.cpp

@@ -1375,9 +1375,12 @@ WebGLContext::WhatDoesVertexAttrib0Need()
 
     // work around Mac OSX crash, see bug 631420
 #ifdef XP_MACOSX
-    if (mAttribBuffers[0].enabled &&
+    if (gl->WorkAroundDriverBugs() &&
+        mAttribBuffers[0].enabled &&
         !mCurrentProgram->IsAttribInUse(0))
+    {
         return VertexAttrib0Status::EmulatedUninitializedArray;
+    }
 #endif
 
     return (gl->IsGLES2() || mAttribBuffers[0].enabled) ? VertexAttrib0Status::Default
@@ -2642,7 +2645,10 @@ WebGLContext::GetProgramParameter(nsIWebGLProgram *pobj, PRUint32 pname, nsIVari
             GLint i = 0;
 #ifdef XP_MACOSX
             // See comment in ValidateProgram below.
-            i = 1;
+            if (gl->WorkAroundDriverBugs())
+                i = 1;
+            else
+                gl->fGetProgramiv(progname, pname, &i);
 #else
             gl->fGetProgramiv(progname, pname, &i);
 #endif
@@ -4397,8 +4403,10 @@ WebGLContext::ValidateProgram(nsIWebGLProgram *pobj)
 
 #ifdef XP_MACOSX
     // see bug 593867 for NVIDIA and bug 657201 for ATI. The latter is confirmed with Mac OS 10.6.7
-    LogMessageIfVerbose("validateProgram: implemented as a no-operation on Mac to work around crashes");
-    return NS_OK;
+    if (gl->WorkAroundDriverBugs()) {
+        LogMessageIfVerbose("validateProgram: implemented as a no-operation on Mac to work around crashes");
+        return NS_OK;
+    }
 #endif
 
     gl->fValidateProgram(progname);
@@ -4506,9 +4514,12 @@ WebGLContext::CompileShader(nsIWebGLShader *sobj)
         // 7-bit ASCII range, so we can skip the NS_IsAscii() check.
         const nsCString& sourceCString = NS_LossyConvertUTF16toASCII(flatSource);
 
-        const PRUint32 maxSourceLength = (PRUint32(1)<<18) - 1;
-        if (sourceCString.Length() > maxSourceLength)
-            return ErrorInvalidValue("compileShader: source has more than %d characters", maxSourceLength);
+        if (gl->WorkAroundDriverBugs()) {
+            const PRUint32 maxSourceLength = (PRUint32(1)<<18) - 1;
+            if (sourceCString.Length() > maxSourceLength)
+                return ErrorInvalidValue("compileShader: source has more than %d characters", 
+                                         maxSourceLength);
+        }
 
         const char *s = sourceCString.get();
 
@@ -4524,8 +4535,12 @@ WebGLContext::CompileShader(nsIWebGLShader *sobj)
                             | SH_ATTRIBUTES_UNIFORMS;
 #ifdef XP_MACOSX
             // work around bug 665578
-            if (!nsCocoaFeatures::OnLionOrLater() && gl->Vendor() == gl::GLContext::VendorATI)
+            if (gl->WorkAroundDriverBugs() &&
+                !nsCocoaFeatures::OnLionOrLater() &&
+                gl->Vendor() == gl::GLContext::VendorATI)
+            {
                 compileOptions |= SH_EMULATE_BUILT_IN_FUNCTIONS;
+            }
 #endif
         }
 

content/canvas/src/WebGLContextValidate.cpp

@@ -641,7 +641,8 @@ WebGLContext::InitAndValidateGL()
         //    http://www.gamedev.net/community/forums/topic.asp?topic_id=525643
         // Also, if the ATI/Windows driver implements a recent GL spec version, this shouldn't be needed anyway.
 #ifdef XP_WIN
-        if (gl->Vendor() != gl::GLContext::VendorATI)
+        if (!(gl->WorkAroundDriverBugs() &&
+              gl->Vendor() == gl::GLContext::VendorATI))
 #else
         if (true)
 #endif

gfx/gl/GLContext.cpp

@@ -126,6 +126,8 @@ GLContext::InitWithPrefix(const char *prefix, bool trygl)
         return true;
     }
 
+    mWorkAroundDriverBugs = gfxPlatform::GetPlatform()->WorkAroundDriverBugs();
+
     SymLoadStruct symbols[] = {
         { (PRFuncPtr*) &mSymbols.fActiveTexture, { "ActiveTexture", "ActiveTextureARB", NULL } },
         { (PRFuncPtr*) &mSymbols.fAttachShader, { "AttachShader", "AttachShaderARB", NULL } },
@@ -501,7 +503,8 @@ GLContext::InitWithPrefix(const char *prefix, bool trygl)
         fGetIntegerv(LOCAL_GL_MAX_RENDERBUFFER_SIZE, &mMaxRenderbufferSize);
 
 #ifdef XP_MACOSX
-        if (mVendor == VendorIntel) {
+        if (mWorkAroundDriverBugs &&
+            mVendor == VendorIntel) {
             // see bug 737182 for 2D textures, bug 684822 for cube map textures.
             mMaxTextureSize        = NS_MIN(mMaxTextureSize,        4096);
             mMaxCubeMapTextureSize = NS_MIN(mMaxCubeMapTextureSize, 512);
@@ -634,6 +637,9 @@ CopyAndPadTextureData(const GLvoid* srcBuffer,
 bool
 GLContext::CanUploadSubTextures()
 {
+    if (!mWorkAroundDriverBugs)
+        return true;
+
     // There are certain GPUs that we don't want to use glTexSubImage2D on
     // because that function can be very slow and/or buggy
     if (Renderer() == RendererAdreno200 || Renderer() == RendererAdreno205)
@@ -650,6 +656,9 @@ GLContext::CanUploadSubTextures()
 bool
 GLContext::CanUploadNonPowerOfTwo()
 {
+    if (!mWorkAroundDriverBugs)
+        return true;
+
     static bool sPowerOfTwoForced;
     static bool sPowerOfTwoPrefCached = false;
 
@@ -673,7 +682,8 @@ GLContext::WantsSmallTiles()
         return true;
 
     // We can't use small tiles on the SGX 540, because of races in texture upload.
-    if (Renderer() == RendererSGX540)
+    if (mWorkAroundDriverBugs &&
+        Renderer() == RendererSGX540)
         return false;
 
     // Don't use small tiles otherwise. (If we implement incremental texture upload,
@@ -2065,7 +2075,9 @@ GLContext::BlitTextureImage(TextureImage *aSrc, const nsIntRect& aSrcRect,
     // only save/restore this stuff on Qualcomm Adreno, to work
     // around an apparent bug
     int savedFb = 0;
-    if (mVendor == VendorQualcomm) {
+    if (mWorkAroundDriverBugs &&
+        mVendor == VendorQualcomm)
+    {
         fGetIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &savedFb);
     }
 
@@ -2200,7 +2212,8 @@ GLContext::BlitTextureImage(TextureImage *aSrc, const nsIntRect& aSrcRect,
     // we enable scissor test while the current FBO is invalid
     // (which it will be, once we assign texture 0 to the color
     // attachment)
-    if (mVendor == VendorQualcomm) {
+    if (mWorkAroundDriverBugs &&
+        mVendor == VendorQualcomm) {
         fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, savedFb);
     }
 

gfx/gl/GLContext.h

@@ -555,7 +555,8 @@ public:
         mMaxTextureSize(0),
         mMaxCubeMapTextureSize(0),
         mMaxTextureImageSize(0),
-        mMaxRenderbufferSize(0)
+        mMaxRenderbufferSize(0),
+        mWorkAroundDriverBugs(true)
 #ifdef DEBUG
         , mGLError(LOCAL_GL_NO_ERROR)
 #endif
@@ -1654,6 +1655,8 @@ protected:
 public:
     void ClearSafely();
 
+    bool WorkAroundDriverBugs() const { return mWorkAroundDriverBugs; }
+
 protected:
 
     nsDataHashtable<nsPtrHashKey<void>, void*> mUserData;
@@ -1685,7 +1688,6 @@ protected:
         return biggerDimension <= maxAllowed;
     }
 
-protected:
     nsTArray<nsIntRect> mViewportStack;
     nsTArray<nsIntRect> mScissorStack;
 
@@ -1693,10 +1695,12 @@ protected:
     GLint mMaxCubeMapTextureSize;
     GLint mMaxTextureImageSize;
     GLint mMaxRenderbufferSize;
+    bool mWorkAroundDriverBugs;
 
     bool IsTextureSizeSafeToPassToDriver(GLenum target, GLsizei width, GLsizei height) const {
 #ifdef XP_MACOSX
-        if (mVendor == VendorIntel) {
+        if (mWorkAroundDriverBugs &&
+            mVendor == VendorIntel) {
             // see bug 737182 for 2D textures, bug 684822 for cube map textures.
             // some drivers handle incorrectly some large texture sizes that are below the
             // max texture size that they report. So we check ourselves against our own values

gfx/thebes/gfxPlatform.cpp

@@ -336,6 +336,8 @@ gfxPlatform::Init()
     gPlatform->mFontPrefsObserver = new FontPrefsObserver();
     Preferences::AddStrongObservers(gPlatform->mFontPrefsObserver, kObservedPrefs);
 
+    gPlatform->mWorkAroundDriverBugs = Preferences::GetBool("gfx.work-around-driver-bugs", true);
+
     // Force registration of the gfx component, thus arranging for
     // ::Shutdown to be called.
     nsCOMPtr<nsISupports> forceReg

gfx/thebes/gfxPlatform.h

@@ -455,6 +455,8 @@ public:
      */
     static PRLogModuleInfo* GetLog(eGfxLog aWhichLog);
 
+    bool WorkAroundDriverBugs() const { return mWorkAroundDriverBugs; }
+
 protected:
     gfxPlatform();
     virtual ~gfxPlatform();
@@ -493,6 +495,7 @@ private:
     nsCOMPtr<nsIObserver> mSRGBOverrideObserver;
     nsCOMPtr<nsIObserver> mFontPrefsObserver;
     mozilla::widget::GfxInfoCollector<gfxPlatform> mAzureBackendCollector;
+    bool mWorkAroundDriverBugs;
 };
 
 #endif /* GFX_PLATFORM_H */

modules/libpref/src/init/all.js

@@ -245,6 +245,8 @@ pref("gfx.canvas.azure.enabled", true);
 pref("gfx.textures.poweroftwo.force-enabled", false);
 #endif
 
+pref("gfx.work-around-driver-bugs", true);
+
 pref("accessibility.browsewithcaret", false);
 pref("accessibility.warn_on_browsewithcaret", true);