Re: [PATCH 4/5] arm64: dts: allwinner: a527: add EMAC0 to Radxa A5E board

From: Andre Przywara
Date: Thu Apr 24 2025 - 09:20:26 EST


On Thu, 24 Apr 2025 14:19:59 +0200
Andrew Lunn <andrew@xxxxxxx> wrote:

Hi Andrew,

> > I'd not bother to try other combinations, and just stick to vendor's
> > settings
>
> Vendors get stuff wrong all the time. Just because it works does not
> mean it is correct. And RGMII delays are very frequently wrong because
> there are multiple ways to get a link which works, but don't follow
> the DT binding.

Speaking of which: do you know of a good method to verify the delay
timing? Is there *something* which is sensitive to those timings and which
can be easily checked and qualified?
I just tried iperf3 yesterday, but didn't spot any real change in the
numbers when toying with those delay values.
As mentioned in the other email, we can easily hack the values at runtime,
so if there is a way to get some "quality" value, this could even be
automated.

Thanks,
Andre