Dual FEC not working - extremely many RX errors

danielkleine-al — Thu, 01 Sep 2016 15:04:35 GMT

Dear community,

we try to get the two FECs on i.MX28 to run. Our hardware setup is that we have two Micrel KSZ8091 PHYs connected with a shared interrupt line. Software-wise we are running a Linux 4.4 kernel.

Our current status is that we

get a link on one or both ethernet interfaces as expected; speed auto-neg works; FEC interrupts work
link down / up (removing and plugging the cable) is working as expected
bootup looks good (both FECs and both PHYs detected and PHYs correctly assigned to the FECs)

The issue now is that whenever only a cable is plugged to eth0 we can send packets (and they look correct according to wireshark) but cannot receive anyhting.

As soon as we additionally connect a cable to eth1 we can send packets on both interfaces correctly and very randomly receive a valid packet; but most of the time only the RX frame error counter (as seen in ifconfig) goes up for eth0 and eth1.

Please let me know if anyone has also seen a similar behaviour or which further information I can provide? Thanks!

Excerpt from device tree:

mac0: ethernet@800f0000 {   phy-mode = "rmii";   phy-handle = <&phy0>;   pinctrl-names = "default";   pinctrl-0 = <&mac0_pins_a &mac0_rx_er>;   phy-supply = <&reg_dummy_3v3>;   phy-reset-gpios = <&gpio4 13 0>;   phy-reset-duration = <100>;   status = "okay";             mdio {     #address-cells = <1>;     #size-cells = <0>;     phy0: ethernet-phy@0 {                 interrupt-parent = <&gpio4>;                 interrupts = <5 8>;                 reg = <0>;     };        phy1: ethernet-phy@3 {                 interrupt-parent = <&gpio4>;                 interrupts = <5 8>;                 reg = <3>;        };        };
};
mac1: ethernet@800f4000 {   phy-mode = "rmii";   phy-handle = <&phy1>;   pinctrl-names = "default";   pinctrl-0 = <&mac1_pins_a &mac1_rx_er>;   phy-supply = <&reg_dummy_3v3>;   status = "okay";};

Re: Dual FEC not working - extremely many RX errors

danielkleine-al — Fri, 02 Sep 2016 10:59:23 GMT

Sorry - we have found the problem, ENET0_RXEN and ENET1_RXEN are interchanged on the layout.

i.MX ProcessorsのトピックRe: Dual FEC not working - extremely many RX errors

Dual FEC not working - extremely many RX errors

Re: Dual FEC not working - extremely many RX errors