stmmac/RTL8211F/Meson GXBB: TX throughput problems

[Martin Blumenstingl]

On Wed, Sep 14, 2016 at 5:30 PM, Giuseppe CAVALLARO
<peppe.cavallaro at st.com> wrote:
> as rule of thumb, I can only suggest you to see the RXDLY and TXDLY
> and if you have (or need!) the resistor on PCB to have the 2ns of
> extra delay. This can impact on RGMII case (1G).
> Indeed, if this is true, I should expect some problem also when ping.
I did a simple ping-test:

device to computer:
50 packets transmitted, 50 received, 0% packet loss, time 50170ms
rtt min/avg/max/mdev = 0.457/0.659/0.779/0.083 ms

computer to device:
50 packets transmitted, 50 received, 0% packet loss, time 49001ms
rtt min/avg/max/mdev = 0.483/0.629/1.356/0.114 ms

both running simultaneously, device to computer:
51 packets transmitted, 50 received, 1% packet loss, time 51182ms
rtt min/avg/max/mdev = 0.459/0.648/0.729/0.082 ms

both running simultaneously, computer to device:
50 packets transmitted, 38 received, 24% packet loss, time 48997ms
rtt min/avg/max/mdev = 0.482/0.594/0.640/0.053 ms