Re: [PATCH v2 1/2] net: phy: microchip: add downshift tunable support for LAN88xx

Russell King (Oracle)
2026-03-31T11:30:15Z

On Tue, Mar 31, 2026 at 12:46:26AM +0200, Nicolai Buchwitz wrote:
> Implement the standard ETHTOOL_PHY_DOWNSHIFT tunable for the LAN88xx
> PHY. This allows runtime configuration of the auto-downshift feature
> via ethtool:
>
> ethtool --set-phy-tunable eth0 downshift on count 3
>
> The LAN88xx PHY supports downshifting from 1000BASE-T to 100BASE-TX
> after 2-5 failed auto-negotiation attempts. Valid count values are
> 2, 3, 4 and 5.
>
> This is based on an earlier downstream implementation by Phil Elwell.
>
> Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>

I didn't see a cover message. Please always include a cover message with
patch series.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Thanks!

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