Subject: Re: [PATCH net] net: phylink: actually fix ksettings_set() ethtool call

From: "Russell King (Oracle)" <[email-masked]>
Date: Thu, 1 Jun 2023 10:05:42 +0100

Please ignore this, wrong version of the patch. :/ More coffee needed.

On Thu, Jun 01, 2023 at 10:02:07AM +0100, Russell King (Oracle) wrote:
> Raju Lakkaraju reported that the below commit caused a regression
> with Lan743x drivers and a 2.5G SFP. Sadly, this is because the commit
> was utterly wrong. Let's fix this properly by not moving the
> linkmode_and(), but instead copying the link ksettings and then
> modifying the advertising mask before passing the modified link
> ksettings to phylib.
> 
> Fixes: df0acdc59b09 ("net: phylink: fix ksettings_set() ethtool call")
> Signed-off-by: Russell King (Oracle) <[email-masked]>
> ---
>  drivers/net/phy/phylink.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index e237949deee6..cf4e51e48cdd 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -2225,11 +2225,13 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
>  
>  	ASSERT_RTNL();
>  
> -	/* Mask out unsupported advertisements */
> -	linkmode_and(config.advertising, kset->link_modes.advertising,
> -		     pl->supported);
> -
>  	if (pl->phydev) {
> +		struct ethtool_link_ksettings phy_kset = *kset;
> +
> +		linkmode_and(phy_kset.link_modes.advertising,
> +			     phy_kset.link_modes.advertising,
> +			     pl->supported);
> +
>  		/* We can rely on phylib for this update; we also do not need
>  		 * to update the pl->link_config settings:
>  		 * - the configuration returned via ksettings_get() will come
> @@ -2252,6 +2254,9 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
>  	}
>  
>  	config = pl->link_config;
> +	/* Mask out unsupported advertisements */
> +	linkmode_and(config.advertising, kset->link_modes.advertising,
> +		     pl->supported);
>  
>  	/* FIXME: should we reject autoneg if phy/mac does not support it? */
>  	switch (kset->base.autoneg) {
> -- 
> 2.30.2
> 
> 

-- 
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