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

Cristian Ciocaltea
2023-12-18T11:44:27Z

On 12/17/23 19:55, Andrew Lunn wrote:
> 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.

Sure, will do, we need a v4 anyway.

Thanks,
Cristian