QGraphicsView background drawing very slow with QGLWidget as a viewport

Hi,

I'm doing a Qt 4.6 application depending heavily on QGraphicsView, and would like to utilize the OpenGL rendering with QGraphicsView.

My QGraphicsView has a tileable background set with QGraphicsView::setBackgroundBrush(), and it works nicely when viewport is a normal QWidget. However, if I set the viewport to be a QGLWidget, the background is at first not drawn at all. If I set QGLWidget::setAutoFillBackground(false) the background is drawn correctly, but performance even on desktop is very slow.

Is there some simple trick I should do to make the performance better, or should I draw the background with OpenGL methods when using QGLWidget as a viewport?

Thanks in advance