[UTOPIC] [PULL] UBUNTU: fix Occasional crash in APM xgene enet driver

[Ming Lei]

Hi Guys,

The 3 patches in below tree fixed one crash in APM xgene enet
driver, please pull that:

        git://kernel.ubuntu.com/ming/ubuntu-utopic.git   arm64-net-backport

Buglink:
             http://bugs.launchpad.net/bugs/1425576

0129e83 drivers: net: xgene: fix: Out of order descriptor bytes read
b53da50 arch: Add lightweight memory barriers dma_rmb() and dma_wmb()
5f34c79 arch: Cleanup read_barrier_depends() and comments

Thanks,
Ming