We are facing issue with micrel ksz9031 when interface with am335x ti sitara processor.
rgmii phy settings and issues below
device tree skew value is listed below
phy0: ethernet-phy@0 {
comptaible = "micrel,ksz9031";
device_type = "ethernet-phy";
rxc-skew-ps = <1500>;
rxdv-skew-ps = <60>;
rxd0-skew-ps = <60>;
rxd1-skew-ps = <0>;
rxd2-skew-ps = <60>;
rxd3-skew-ps = <0>;
txc-skew-ps = <1860>;
txen-skew-ps = <0>;
txd0-skew-ps = <0>;
txd1-skew-ps = <0>;
txd2-skew-ps = <0>;
txd3-skew-ps = <0>;
reg = <0>;
}
we calculated from as below
| Device tree val | |||||||||
| in mils | in metre | speed in m/s | delay | skew | final skew | DELAY 1.38NS | |||
| Tclk | 1191 | 3.03E-002 | 1.89E+008 | 1.60060317460317E-010 | 0 | 0 | 1860 | ||
| Tcntl | 1174.56 | 2.98E-002 | 1.89E+008 | 1.57850919799731E-010 | 2.20939766058689E-012 | 2.2ps | 0 | ||
| TD0 | 1173.08 | 2.98E-002 | 1.89E+008 | 1.57652019495746E-010 | -2.40829796457166E-012 | -2.44ps | 0 | ||
| TD1 | 1158.48 | 2.94E-002 | 1.89E+008 | 1.55689902290636E-010 | -4.37041516968098E-012 | -4.37ps | 0 | ||
| TD2 | 1191.03 | 3.03E-002 | 1.89E+008 | 1.60064345818744E-010 | 4.02835842653473E-015 | 0 | 0 | ||
| TD3 | 1181.3 | 3.00E-002 | 1.89E+008 | 1.58756715376806E-010 | -1.303602083511E-012 | -1.3ps | 0 | ||
| in mils | in metre | speed in m/s | delay | skew | final skew | Delay 1.8 | |||
| Rclk | 935.94 | 2.38E-002 | 1.89E+008 | 1.25782412698413E-010 | 0 | 0 | 1500 | ||
| Rcntl | 996.79 | 2.53E-002 | 1.89E+008 | 1.33960136857354E-010 | -8.17772415894107E-012 | -8.2ps | 60 | ||
| RD0 | 943.93 | 2.40E-002 | 1.89E+008 | 1.26856199715807E-010 | 1.0737870173947E-012 | 1.3ps | 60 | ||
| RD1 | 654.42 | 1.66E-002 | 1.89E+008 | 8.79485065404999E-011 | -3.78339061579128E-011 | -37ps | 0 | ||
| RD2 | 1040.79 | 2.64E-002 | 1.89E+008 | 1.39873362119082E-010 | 1.40909494206696E-011 | 14ps | 60 | ||
| RD3 | 593.91 | 1.51E-002 | 1.89E+008 | 7.98164740789293E-011 | -4.59659386194835E-011 | -46ps | 0 |
We have 10/100 mbs working fine with or without setting these skew values. But when we try with 1G we are continuously getting Link up and Link down message and not having it properly auto-negotiated to 1G
I can see there the Rx clock and Tx clock setting properly to 125 MHz but the next second both these clk's returns to 25 Mhz. Can you assist why this auto-negotiation link up and link down is happening continuously.
I've already applied the patch https://lkml.org/lkml/2015/6/5/767 in my driver for link stability. And also tried with different hub.
the kernel log from am335x cpsw driver cpsw.c below
[ 45.680192] _cpsw_adjust_link slave_num 0
[ 45.684772] PHY mac_control 20 speed 1000
[ 45.688802] PHY mac_control != slave->mac_control REG Set
[ 45.694296] cpsw 4a100000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[ 47.699988] _cpsw_adjust_link slave_num 0
[ 47.704563] PHY link down
[ 47.707198] PHY mac_control != slave->mac_control REG Set
[ 47.712682] cpsw 4a100000.ethernet eth0: Link is Down
[ 47.717762] CPSW STOPPING CARRIER
[ 49.720130] cpsw_adjust_link slave_num 0
[ 49.724706] PHY mac_control 20 speed 1000
[ 49.728736] PHY mac_control != slave->mac_control REG Set
[ 49.734306] cpsw 4a100000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[ 51.740004] _cpsw_adjust_link slave_num 0
[ 51.744578] PHY link down
[ 51.747212] PHY mac_control != slave->mac_control REG Set
[ 51.752696] cpsw 4a100000.ethernet eth0: Link is Down
[ 51.757777] CPSW STOPPING CARRIER
This is a continuous message.
Please let us know how we can solve this issue.
regards
nilesh
