From 12e88e486b2a38272c0e9a5402b2af708339b8a3 Mon Sep 17 00:00:00 2001
From: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Date: Fri, 13 Mar 2015 14:33:47 +0100
Subject: [PATCH] Disable DSA on Radeon

Try to prevent crashes on Windows and broken textures on Linux.

Task-number: QTBUG-40653
Task-number: QTBUG-44988
Change-Id: I1fd259ba5ca3980c3087411e1dae1ae56bb2c2e4
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
---
 src/gui/opengl/qopengltexturehelper.cpp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/gui/opengl/qopengltexturehelper.cpp b/src/gui/opengl/qopengltexturehelper.cpp
index 386c4af232..3635a7dd1b 100644
--- a/src/gui/opengl/qopengltexturehelper.cpp
+++ b/src/gui/opengl/qopengltexturehelper.cpp
@@ -40,8 +40,16 @@ QT_BEGIN_NAMESPACE
 
 QOpenGLTextureHelper::QOpenGLTextureHelper(QOpenGLContext *context)
 {
-    // Resolve EXT_direct_state_access entry points if present
-    if (!context->isOpenGLES()
+    // Resolve EXT_direct_state_access entry points if present.
+
+    // However, disable it on some systems where DSA is known to be unreliable.
+    bool allowDSA = true;
+    const char *renderer = reinterpret_cast<const char *>(context->functions()->glGetString(GL_RENDERER));
+    // QTBUG-40653, QTBUG-44988
+    if (renderer && strstr(renderer, "AMD Radeon HD"))
+        allowDSA = false;
+
+    if (allowDSA && !context->isOpenGLES()
         && context->hasExtension(QByteArrayLiteral("GL_EXT_direct_state_access"))) {
         TextureParameteriEXT = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLuint , GLenum , GLenum , GLint )>(context->getProcAddress(QByteArrayLiteral("glTextureParameteriEXT")));
         TextureParameterivEXT = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLuint , GLenum , GLenum , const GLint *)>(context->getProcAddress(QByteArrayLiteral("glTextureParameterivEXT")));