net: socionext: remove mmio reads on Tx
Currently the driver issues 2 mmio reads to figure out the number of
transmitted packets and clean them. We can get rid of the expensive
reads since BIT 31 of the Tx descriptor can be used for that.
We can also remove the budget counting of Tx completions since all of
the descriptors are not deliberately processed.
Performance numbers using pktgen are:
size pre-patch(pps) post-patch(pps)
64 362483 427916
128 358315 411686
256 352725 389683
512 215675 216464
1024 113812 114442
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>