On Thu, 2016-11-24 at 15:34 +0100, Martin Blumenstingl wrote: > Currently the dwmac-meson8b stmmac glue driver uses a hardcoded 1/4 > cycle 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... > > This raises a question though: > Which device is supposed to enable the TX delay when both MAC and PHY > support it? And should we implement it for each PHY / MAC separately > or should we think about a more generic solution (currently it's not > possible to disable the TX delay generated by the RTL8211F PHY via > devicetree when using phy-mode "rgmii")? > > 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: > $ iperf3 -c 192.168.1.100 -R > Connecting to host 192.168.1.100, port 5201 > Reverse mode, remote host 192.168.1.100 is sending > [ 4] local 192.168.1.206 port 52828 connected to 192.168.1.100 port > 5201 > [ ID] Interval Transfer Bandwidth > [ 4] 0.00-1.00 sec 108 MBytes 901 > Mbits/sec > [ 4] 1.00-2.00 sec 94.2 MBytes 791 > Mbits/sec > [ 4] 2.00-3.00 sec 96.5 MBytes 810 > Mbits/sec > [ 4] 3.00-4.00 sec 96.2 MBytes 808 > Mbits/sec > [ 4] 4.00-5.00 sec 96.6 MBytes 810 > Mbits/sec > [ 4] 5.00-6.00 sec 96.5 MBytes 810 > Mbits/sec > [ 4] 6.00-7.00 sec 96.6 MBytes 810 > Mbits/sec > [ 4] 7.00-8.00 sec 96.5 MBytes 809 > Mbits/sec > [ 4] 8.00-9.00 sec 105 MBytes 884 > Mbits/sec > [ 4] 9.00-10.00 sec 111 MBytes 934 > Mbits/sec > - - - - - - - - - - - - - - - - - - - - - - - - - > [ ID] Interval Transfer Bandwidth Retr > [ 4] 0.00-10.00 sec 1000 MBytes 839 > Mbits/sec 0 sender > [ 4] 0.00-10.00 sec 998 MBytes 837 > Mbits/sec receiver > > iperf Done. > $ iperf3 -c 192.168.1.100 > Connecting to host 192.168.1.100, port 5201 > [ 4] local 192.168.1.206 port 52832 connected to 192.168.1.100 port > 5201 > [ ID] Interval Transfer Bandwidth Retr Cwnd > [ 4] 0.00-1.01 sec 99.5 MBytes 829 Mbits/sec 117 139 > KBytes > [ 4] 1.01-2.00 sec 105 MBytes 884 Mbits/sec 129 70.7 > KBytes > [ 4] 2.00-3.01 sec 107 MBytes 889 Mbits/sec 106 187 > KBytes > [ 4] 3.01-4.01 sec 105 MBytes 878 Mbits/sec 92 143 > KBytes > [ 4] 4.01-5.00 sec 105 MBytes 882 Mbits/sec 140 129 > KBytes > [ 4] 5.00-6.01 sec 106 MBytes 883 Mbits/sec 115 195 > KBytes > [ 4] 6.01-7.00 sec 102 MBytes 863 Mbits/sec 133 70.7 > KBytes > [ 4] 7.00-8.01 sec 106 MBytes 884 Mbits/sec 143 97.6 > KBytes > [ 4] 8.01-9.01 sec 104 MBytes 875 Mbits/sec 124 107 > KBytes > [ 4] 9.01-10.01 sec 105 MBytes 876 Mbits/sec 90 139 > KBytes > - - - - - - - - - - - - - - - - - - - - - - - - - > [ ID] Interval Transfer Bandwidth Retr > [ 4] 0.00-10.01 sec 1.02 GBytes 874 > Mbits/sec 1189 sender > [ 4] 0.00-10.01 sec 1.02 GBytes 873 > Mbits/sec receiver > Cool, one more board working ;) I tried your patch on another board (MXQ_V2.1, with sheep printed on the PCB). It 's not improving the situation for this one unfortunately. Actually I already tried playing with the TX delay on the MAC and PHY but I could get any good results with the boards I have. It is strange that we can adjust the delay by 2ns steps, when delay seens by the phy should be 2ns ... > iperf Done. > > > Martin Blumenstingl (2): > net: dt-bindings: add RGMII TX delay configuration to meson8b-dwmac > net: stmmac: dwmac-meson8b: make the RGMII TX delay configurable > > Documentation/devicetree/bindings/net/meson-dwmac.txt | 11 > +++++++++++ > drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c | 16 > +++++++++++----- > include/dt-bindings/net/dwmac-meson8b.h | 18 > ++++++++++++++++++ > 3 files changed, 40 insertions(+), 5 deletions(-) > create mode 100644 include/dt-bindings/net/dwmac-meson8b.h > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
