Adding read memory barrier in between flag reading and data reading of
receive descriptors. This prevents the data being read before hardware
complete writing informations.
Reported-by: NStefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NGuo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>