Re: [PATCH v3 6/9] riscv: dts: starfive: visionfive-v1: Setup ethernet phy

Andrew Lunn
2023-12-17T17:56:09Z

On Fri, Dec 15, 2023 at 10:40:45PM +0200, Cristian Ciocaltea wrote:
> The StarFive VisionFive V1 SBC uses a Motorcomm YT8521 PHY supporting
> RGMII-ID, but requires manual adjustment of the RX internal delay to
> work properly.
>
> The default RX delay provided by the driver is 1.95 ns, which proves to
> be too high. Applying a 50% reduction seems to mitigate the issue.
>
> Also note this adjustment is not necessary on BeagleV Starlight SBC,
> which uses a Microchip PHY. Hence, there is no indication of a
> miss-behaviour on the GMAC side, but most likely the issue stems from
> the Motorcomm PHY.

I suggest you make a similar comment in the .dts file, just to explain
the odd setting.

Andrew