2021-06-07 13:11:54

by Russell King (Oracle)

[permalink] [raw]
Subject: Re: [PATCH net-next v3 03/10] net: sparx5: add hostmode with phylink support

On Mon, Jun 07, 2021 at 02:45:01PM +0200, Steen Hegelund wrote:
> Hi Russell,
>
> Thanks for your comments.
>
> On Mon, 2021-06-07 at 10:15 +0100, Russell King (Oracle) wrote:
> > 3) I really don't get what's going on with setting the port mode to
> > 2500base-X and 1000base-X here when state->interface is 10GBASER.
>
> The high speed interfaces (> 2.5G) do not support any in-band signalling, so the only way that e.g a
> 10G interface running at 2.5G will be able to link up with its partner is if both ends configure the
> speed manually via ethtool.

We really should not have drivers hacking around in this way. If we want
to operate in 2500base-x or 1000base-x, then that is what phylink should
be telling the MAC driver. The MAC driver should not be making these
decisions in its mac_config() callback. Doing so makes a joke of kernel
programming.

--
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