RE: [PATCH net v2 1/1] ethtool: netlink: do not return SQI value if link is down

[Woojung.Huh]

Hi Oleksij,

> diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c
> index b2de2108b356a..4efd327ba5d92 100644
> --- a/net/ethtool/linkstate.c
> +++ b/net/ethtool/linkstate.c
> @@ -37,6 +37,8 @@ static int linkstate_get_sqi(struct net_device *dev)
>         mutex_lock(&phydev->lock);
>         if (!phydev->drv || !phydev->drv->get_sqi)
>                 ret = -EOPNOTSUPP;
> +       else if (!phydev->link)
> +               ret = -ENETDOWN;
>         else
>                 ret = phydev->drv->get_sqi(phydev);
>         mutex_unlock(&phydev->lock);
> @@ -55,6 +57,8 @@ static int linkstate_get_sqi_max(struct net_device *dev)
>         mutex_lock(&phydev->lock);
>         if (!phydev->drv || !phydev->drv->get_sqi_max)
>                 ret = -EOPNOTSUPP;
> +       else if (!phydev->link)
> +               ret = -ENETDOWN;
>         else
>                 ret = phydev->drv->get_sqi_max(phydev);
>         mutex_unlock(&phydev->lock);
> @@ -62,6 +66,16 @@ static int linkstate_get_sqi_max(struct net_device *dev)
>         return ret;
>  };
> 
> +static bool linkstate_sqi_critical_error(int sqi)
> +{
> +       return sqi < 0 && sqi != -EOPNOTSUPP && sqi != -ENETDOWN;
> +}
> +
> +static bool linkstate_sqi_valid(struct linkstate_reply_data *data)
> +{
> +       return data->sqi >= 0 && data->sqi_max >= 0;

If PHY driver has get_sqi, but not get_sqi_max, then data->sqi could have
a valid value, but data->sqi_max will have -EOPNOTSUPP.
In this case, linkstate_sqi_valid() will return FALSE and not getting 
SQI value at all.

If both APIs are required, then we could add another condition of
data->sqi <= data->sqi_max in linkstate_sqi_valid()

And, beside this, calling linkstate_get_sqi and linkstate_get_sqi_max
could be moved under "if (dev->flags & IFF_UP)" with setting default 
value to data->sqi & data->sqi_max.


> +}
> +

Thanks.
Woojung