am 46820412: am 8eb16af2: Merge "don\'t try to lock a buffer that wasn\'t allocated with SW usage bits" into gingerbread

Merge commit '468204124e95bbf74ae8cc000318ade29e311be6'

* commit '468204124e95bbf74ae8cc000318ade29e311be6':
  don't try to lock a buffer that wasn't allocated with SW usage bits