qt6-webengine/disable-gpu-when-using-nouveau-boo-1005323.diff

From: Antonio Larrosa <alarrosa@suse.com>
Subject: Disable GPU when using nouveau or running on wayland
References: boo#1005323, boo#1060990

Qt WebEngine uses multi-threaded OpenGL, which nouveau does not support.
It also crashes when running on wayland, the cause is not yet known.
Work around these issues by not doing GPU-accelerated rendering in such
cases.

diff --git a/src/core/web_engine_context.cpp b/src/core/web_engine_context.cpp
index c9f82c31..0f92e3de 100644
--- a/src/core/web_engine_context.cpp
+++ b/src/core/web_engine_context.cpp
@@ -133,6 +133,7 @@
 #include <QOffscreenSurface>
 #if QT_CONFIG(opengl)
 # include <QOpenGLContext>
+# include <QOpenGLFunctions>
 # include <qopenglcontext_platform.h>
 #endif
 #include <QQuickWindow>
@@ -206,11 +207,33 @@ bool usingSoftwareDynamicGL()
 static const char *getGLType(bool enableGLSoftwareRendering)
 {
     const char *glType = nullptr;
+
+    bool disableGpu = qEnvironmentVariableIsSet("QT_WEBENGINE_DISABLE_GPU");
+
+    if (!qEnvironmentVariableIsSet("QT_WEBENGINE_DISABLE_WAYLAND_WORKAROUND") && qApp->platformName().startsWith("wayland", Qt::CaseInsensitive))
+    {
+        qWarning() << "Running on wayland. Qt WebEngine will disable usage of the GPU.\n"
+                      "Note: you can set the QT_WEBENGINE_DISABLE_WAYLAND_WORKAROUND\n"
+                      "environment variable before running this application, but this is \n"
+                      "not recommended since this usually causes applications to crash.";
+        disableGpu = true;
+    }
+
+    if (!qEnvironmentVariableIsSet("QT_WEBENGINE_DISABLE_NOUVEAU_WORKAROUND") && openGLVendor() == QStringLiteral("nouveau"))
+    {
+        qWarning() << "Nouveau openGL driver detected. Qt WebEngine will disable usage of the GPU.\n"
+                      "Note: you can set the QT_WEBENGINE_DISABLE_NOUVEAU_WORKAROUND\n"
+                      "environment variable before running this application, but this is \n"
+                      "not recommended since this usually causes applications to crash as\n"
+                      "Nouveau openGL drivers don't support multithreaded rendering";
+        disableGpu = true;
+    }
+
     const bool tryGL = (usingDefaultSGBackend() && !usingSoftwareDynamicGL()
                         && QGuiApplicationPrivate::platformIntegration()->hasCapability(
                                 QPlatformIntegration::OpenGL))
             || enableGLSoftwareRendering;
-    if (tryGL) {
+    if (tryGL && !disableGpu) {
         if (!qt_gl_global_share_context() || !qt_gl_global_share_context()->isValid()) {
             qWarning("WebEngineContext used before QtWebEngineCore::initialize() or OpenGL context "
                      "creation failed.");
@@ -914,6 +937,39 @@ base::CommandLine* WebEngineContext::commandLine() {
     }
 }
 
+#ifndef QT_NO_OPENGL
+QString openGLVendor()
+{
+    QString vendor;
+
+    QOpenGLContext *oldContext = QOpenGLContext::currentContext();
+    QSurface *oldSurface = 0;
+    if (oldContext)
+        oldSurface = oldContext->surface();
+
+    QScopedPointer<QOffscreenSurface> surface( new QOffscreenSurface );
+    surface->create();
+    QOpenGLContext context;
+    if (!context.create()) {
+        qDebug() << "Error creating openGL context";
+    }
+    else if (!context.makeCurrent(surface.data())) {
+        qDebug() << "Error making openGL context current context";
+    } else {
+        const GLubyte *p;
+        QOpenGLFunctions *f = context.functions();
+        if ((p = f->glGetString(GL_VENDOR)))
+            vendor = QString::fromLatin1(reinterpret_cast<const char *>(p));
+    }
+
+    context.doneCurrent();
+    if (oldContext && oldSurface)
+        oldContext->makeCurrent(oldSurface);
+
+    return vendor;
+}
+#endif
+
 } // namespace
 
 QT_BEGIN_NAMESPACE