imx6ul dual ethernet mdio on fec1issue

[Blackrose]

Dear all:

I use imx6ul chip on our custom board.I reference the imx6ulevk board sch and code, the mdio on fec2.In this case, the fec2 is eth0, fec1 is eth1.Now, i config the mdio on fec1 pinctrl.But the eth0 and eth1 always show device not found.And i know the mdio is share with fec1 and fec2.

I search an patch for imx28, it said use FEC_QUIRK_SINGLE_MDIO can use mdio on fec1 or fec2 anytime.I try it, but failed.Here is the patch url:

[PATCH v2] net: fec: fix MDIO bus assignement for dual fec SoC's 

Is it the fec driver can not support mdio on fec1 at dual ethernet case?

[Carlos_Musich]

Hi Blackrose,

Rather than the driver, it is not possible to use the 2 FECs with one single MII / RMII / RGMII interface because the pins are connected internally to each FEC.

Best regards,
Carlos

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[Blackrose]

Thanks.I doesn't found those note on datasheet of chip.

[Carlos_Musich]

Hi Blackrose,

It is not quit explicit but you can infer it if you look at in the Reference Manual at Table 22-1. ENET1 External Signals and Table 22-2. ENET2 External Signals.

Here you can see that most of the signals are available in only one pin, and this pin has no Mux options.

Best regards,
Carlos

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