回覆: 回覆: [net-next 2/4] ARM: dts: ast2600-evb: add default RGMII delay
Jacky Chou
jacky_chou at aspeedtech.com
Thu Mar 20 19:02:52 AEDT 2025
Hi Andrew,
> DT describes the board. Does the board add the 2ns delay via extra long clock
> lines? If yes, use rgmii. If the MAC/PHY pair need to add the 2ns delay, use
> rgmii-id.
>
> If the MAC/PHY pair is adding the delay, the DT says nothing about how they
> add the delay.
>
> The general rule is the PHY adds the delay. If you look at drivers/net/phy/*.c,
> every PHY that implements RGMII support both
> PHY_INTERFACE_MODE_RGMII_ID and PHY_INTERFACE_MODE_RGMII. There
> is no reason not to follow ever other MAC/PHY pair and have the PHY add the
> delay. The MAC can then do fine tuning if needed, adding small delays.
Thank you for your reply and information.
We will discuss internal and modify in next version.
Thanks,
Jacky
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