Some days ago I read news about a new Raspberry Pi open source video driver being officially integrated into the Linux Kernel. I found the website http://dri.freedesktop.org/wiki/VC4/ which links to another site with ready-to-use Raspbian images which use the new driver: http://sukzessiv.net/~gohai/vc4-buildbot/build/
However, that custom Raspbian has major issues. The whole OS seems to freeze whenever you scroll a web page (the default browser won't even start), create a large selection rectangle on the desktop, or move windows. I wonder if the driver which is already included in the Linux 4.4 Kernel is that buggy, too.
Furthermore, I couldn't start or compile any application that tries to display a little more than basic unaccelerated 2D. Video players, emulators, and such.
All browsers I tried (Iceweasel, NetSurf, Dillo, Links2) except Ubuntu ARM Chromium with hardware acceleration enabled trigger the scroll-freeze bug.
Did anyone of you try or still use this new driver with different results?