IngenicSemiconductor/KERNEL-NPM801 — pull request #3 by piet-delaney (2013-08-21 08:27:08+00:00)
Title: [MIPS] mem->size from ioctl could be zero, protect against that.

New codec code seem to send a mem->size == 0 in an ioctl.
Kernel needs to protect itself. Can't call dma_cache_wback()
with a size of zero; it will panic with a stack that isn't
in good shape to see that the origin of the problem was here.

Signed-off-by: Pete Delaney