https://bugs.freedesktop.org/show_bug.cgi?id=60879
--- Comment #59 from Michel Dänzer michel@daenzer.net --- (In reply to comment #58)
Default raster_config = 0x2a00126a rb mask = 255 Final raster_config = 0x2a00126a
The patch didn't modify the raster_config value, so either it's not correct yet, or the kernel is providing incorrect information about which backends are enabled.