On Fri, Oct 17, 2025 at 06:10:10PM +0200, Buday Csaba wrote:
> Some Ethernet PHYs require a hard reset before accessing their MDIO
> registers. When the ID is not provided by a compatible string,
> reading the PHY ID may fail on such devices.
>
> This patch introduces a new device tree property called
> `phy-id-read-needs-reset`, which can be used to hard reset the
> PHY before attempting to read its ID via MDIO.
If your phy needs special handling, provide a compatible and use that.
>
> Signed-off-by: Buday Csaba <buday.csaba@prolan.hu>
> ---
> V2 -> V3: unchanged
> V1 -> V2: added this DT binding
> ---
> Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> index 2ec2d9fda..b570f8038 100644
> --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> @@ -215,6 +215,14 @@ properties:
> Delay after the reset was deasserted in microseconds. If
> this property is missing the delay will be skipped.
>
> + phy-id-read-needs-reset:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description:
> + Some PHYs require a hard reset before accessing MDIO registers.
> + This workaround allows auto-detection of the PHY ID in such cases.
> + When the PHY ID is provided with the 'compatible' string, setting
> + this property has no effect.
> +
> sfp:
> $ref: /schemas/types.yaml#/definitions/phandle
> description:
> --
> 2.39.5
>
>