https://bugs.freedesktop.org/show_bug.cgi?id=57350
--- Comment #4 from David Herrmann dh.herrmann@gmail.com --- I can provoke this bug with a simple drmModeSetCursor() or drmModeMoveCursor(). The cursor images have a horizontal black stripe (not always). Position varies on my machine. Using 3D acceleration without cursors works perfectly well (although starting mplayer caused a deadlock on my machine).
It's also a nv50 card.
I tried bisecting it and it turns out the memory-manager rewrite caused it (as reported on IRC). I was unable to revert the commit on top of 3.7 as it is quite complex.