From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerome Brunet Subject: Re: [net-next PATCH v1 0/2] stmmac: dwmac-meson8b: configurable RGMII TX delay Date: Thu, 24 Nov 2016 16:56:04 +0100 Message-ID: <1480002964.17538.131.camel@baylibre.com> References: <20161124143417.10178-1-martin.blumenstingl@googlemail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20161124143417.10178-1-martin.blumenstingl@googlemail.com> Sender: netdev-owner@vger.kernel.org To: Martin Blumenstingl , linux-amlogic@lists.infradead.org, devicetree@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net, khilman@baylibre.com, mark.rutland@arm.com, robh+dt@kernel.org Cc: linux-arm-kernel@lists.infradead.org, alexandre.torgue@st.com, peppe.cavallaro@st.com, carlo@caione.org List-Id: devicetree@vger.kernel.org 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")? Actually you can skip the part which activate the Tx-delay on the phy by setting "phy-mode = "rgmii-id" instead of "rgmii" phy->interface will no longer be PHY_INTERFACE_MODE_RGMII but PHY_INTERFACE_MODE_RGMII_ID. > > 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 > > 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 >