Hi Oleksij,
On Tue, Oct 6, 2020 at 5:05 AM Oleksij Rempel <o.rem...@pengutronix.de> wrote:
>
> Hello PHY experts,
>
> Short version:
> what is the proper way to handle the PHY reset before identifying PHY?
>
> Long version:
> I stumbled over following issue:
> If PHY reset is registered within PHY node. Then, sometimes, we will not be
> able to identify it (read PHY ID), because PHY is under reset.
>
> mdio {
> compatible = "virtual,mdio-gpio";
>
> [...]
>
> /* Microchip KSZ8081 */
> usbeth_phy: ethernet-phy@3 {
> reg = <0x3>;
>
> interrupts-extended = <&gpio5 12 IRQ_TYPE_LEVEL_LOW>;
> reset-gpios = <&gpio5 11 GPIO_ACTIVE_LOW>;
> reset-assert-us = <500>;
> reset-deassert-us = <1000>;
> };
>
> [...]
> };
>
> On simple boards with one PHY per MDIO bus, it is easy to workaround by using
> phy-reset-gpios withing MAC node (illustrated in below DT example), instead of
> using reset-gpios within PHY node (see above DT example).
>
> &fec {
> [...]
> phy-mode = "rmii";
> phy-reset-gpios = <&gpio4 12 GPIO_ACTIVE_LOW>;
> [...]
I thought this has been fixed by Bruno's series:
https://www.spinics.net/lists/netdev/msg673611.html
