Re: [PATCH net-next v5 0/2] stmmac: dwmac-meson8b: configurable RGMII TX delay

From: Martin Blumenstingl <martin.blumenstingl-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
Date: Sun, 22 Jan 2017 23:02:44 +0100

Currently the dwmac-meson8b stmmac glue driver uses a hardcoded 1/4
cycle (= 2ns) TX clock delay. This seems to work fine for many boards
(for example Odroid-C2 or Amlogic's reference boards) but there are
some others where TX traffic is simply broken.
There are probably multiple reasons why it's working on some boards
while it's broken on others:
- some of Amlogic's reference boards are using a Micrel PHY
- hardware circuit design
- maybe more...

iperf3 results on my Mecool BB2 board (Meson GXM, RTL8211F PHY) with
TX clock delay disabled on the MAC (as it's enabled in the PHY driver).
TX throughput was virtually zero before:

 ...

I get similar TX throughput on my Meson GXBB "MXQ Pro+" board when I
disable the PHY's TX-delay and configure a 4ms TX-delay on the MAC.
So changes to at least the RTL8211F PHY driver are needed to get it
working properly in all situations.

Series applied, thanks.
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