Subject: Re: [PATCH ethtool 2/2] Ethtool: Implements ETHTOOL_PHY_GTUNABLE/ETHTOOL_PHY_STUNABLE and PHY downshift

From: Andrew Lunn <[email-masked]>
Date: Fri, 4 Nov 2016 12:59:37 +0100

Hi Allen

> +++ b/ethtool.8.in
> @@ -340,6 +340,14 @@ ethtool \- query or control network driver and hardware settings
>  .B2 tx-lpi on off
>  .BN tx-timer
>  .BN advertise
> +.HP
> +.B ethtool \-\-set\-phy\-tunable
> +.I devname
> +.B3 downshift on off N
> +.HP

I don't think there is any other option which is on|off|N. The general
pattern would be

--set-phy-tunable downshift on|off [count N]

With count being optional.

This also allows avoiding the ambiguity of what

--set-phy-tunable downshift 0

means. To me, that means downshift after 0 retries. But it actually
seems to mean never downshift. You can then error out when somebody
does

--set-phy-tunable downshift on count 0
or
--set-phy-tunable downshift off count 42

Please also add a few sentences about what downshift is, and what N
means. Is it tries, or retries?

Thanks
       Andrew