From fa25f7a3bbe993e6f1ced8fa09badb5050349683 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Thu, 28 Feb 2013 08:49:36 +0100
Subject: [PATCH] Disable Lanczos for IvyBridge with Mesa 9.1

I don't like to do it, but it's better than users getting a bad
performance experience.

The change should be reverted once the issue is identified and fixed.

CCBUG: 313613
REVIEW: 109200
---
 lanczosfilter.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lanczosfilter.cpp b/lanczosfilter.cpp
index 75b9f9247a..ef79837f6c 100644
--- a/lanczosfilter.cpp
+++ b/lanczosfilter.cpp
@@ -67,6 +67,9 @@ void LanczosFilter::init()
     GLPlatform *gl = GLPlatform::instance();
     if (!force && gl->driver() == Driver_Intel && gl->chipClass() < SandyBridge)
         return;
+    // Broken on IvyBridge with Mesa 9.1 - BUG 313613
+    if (!force && gl->driver() == Driver_Intel && gl->chipClass() == IvyBridge && gl->mesaVersion() >= kVersionNumber(9, 1))
+        return;
     // With fglrx the ARB Shader crashes KWin (see Bug #270818 and #286795)
     if (!force && gl->driver() == Driver_Catalyst && effects->compositingType() == OpenGL1Compositing) {
         return;