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

David Miller davem at davemloft.net
Tue Jan 24 10:36:13 PST 2017


From: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
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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