Re: [RFC PATCH 0/1] net: phy: skip autoneg of ethernet(fec) on network boot

From: Andrew Lunn
Date: Mon Jul 09 2018 - 10:41:14 EST


On Mon, Jul 09, 2018 at 06:29:02PM +0900, Masahiko KIMOTO wrote:
> Hello Florian,
>
> > I completely acknowledge and support the use case, but your
> > implementation is definitively not the way to go. In my experience the
> > problem is usually that there may be a disagreement on the
> > Pause/Asym_Pause advertisement bits and that alone is responsible for
> > triggering a re-negotiation. Can yo check if that is the case here?
>
> Thank you for your support.
>
> Concening the problem about PAUSE/Asym_PAUSE advertisement you pointed out,
> I could not understand your consideration.
>
> Would you tell me more detail about it?

Hi Masahiko

You said that the PHY is being configured 3 times, and might be doing
auto-neg three times. Often a phy will not actually perform auto-neg,
or do it much faster, if the advertised bits do not change with each
re-configuration.

So check how u-boot is configuring what is advertised, and look at
what Linux is configuring. In particularly, look at the pause
configuration. If pause is configured different in u-boot and Linux,
try to make it the same. Things might go faster than.

Andrew