Re: [PATCH net-next v9 02/15] net: ethtool: common: Indicate that BaseT works on up to 4 lanes

[Kory Maincent <kory.maincent@bootlin.com>]

Le Thu, 17 Jul 2025 09:30:06 +0200,
Maxime Chevallier <maxime.chevallier@bootlin.com> a écrit :

> The way BaseT modes (Ethernet over twisted copper pairs) are represented
> in the kernel are through the following modes :
> 
>   ETHTOOL_LINK_MODE_10baseT_Half
>   ETHTOOL_LINK_MODE_10baseT_Full
>   ETHTOOL_LINK_MODE_100baseT_Half
>   ETHTOOL_LINK_MODE_100baseT_Full
>   ETHTOOL_LINK_MODE_1000baseT_Half
>   ETHTOOL_LINK_MODE_1000baseT_Full
>   ETHTOOL_LINK_MODE_2500baseT_Full
>   ETHTOOL_LINK_MODE_5000baseT_Full
>   ETHTOOL_LINK_MODE_10000baseT_Full
>   ETHTOOL_LINK_MODE_100baseT1_Full
>   ETHTOOL_LINK_MODE_1000baseT1_Full
>   ETHTOOL_LINK_MODE_10baseT1L_Full
>   ETHTOOL_LINK_MODE_10baseT1S_Full
>   ETHTOOL_LINK_MODE_10baseT1S_Half
>   ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half
>   ETHTOOL_LINK_MODE_10baseT1BRR_Full
> 
> The baseT1* modes explicitly specify that they work on a single,
> unshielded twister copper pair.
> 
> However, the other modes do not state the number of pairs that are used
> to carry the link. 10 and 100BaseT use 2 twisted copper pairs, while
> 1GBaseT and higher use 4 pairs.
> 
> although 10 and 100BaseT use 2 pairs, they can work on a Cat3/4/5+
> cables that contain 4 pairs.
> 
> Change the number of pairs associated to BaseT modes to indicate the
> allowable number of pairs for BaseT. Further commits will then refine
> the minimum number of pairs required for the linkmode to work.
> 
> BaseT1 modes aren't affected by this commit.
> 
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>

Thank you!

-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com