Re: [PATCH 5/5] ARM: dts: aspeed: Add Facebook Darwin (AST2600) BMC

Andrew Lunn
2025-07-03T07:59:15Z

> > How do RGMII delays work? Connections to switches have to be handled
> > different to PHYs, to avoid double delays. But is there extra long
> > clock lines? Or are you expecting the switch to add the delays?
> >
> > Andrew
>
> Hi Andrew,
>
> The delays are introduced in BMC MAC by setting SCU control registers in
> u-boot. The delays on the switch side are disabled.

Sorry, but not acceptable. This is something i've been NACKing Aspeed
DT patches for. You need the MAC driver to interpret the phy-mode and
program the SCU control register as needed.

Since you have the MAC introducing the delays, you want phy-mode
'rgmii-id'.

If you want to submit some DT now, drop the ethernet node. This is
what others have been doing while waiting for Aspeed to fix their MAC
driver. Having said that, i've not seen any progress from Aspeed, so
it either needs their customers to apply more pressure, or somebody in
the community to just fix it and submit patches.

Andrew

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pw-bot: cr