Subject: Re: [PATCH net v2] net: phy: phy_ethtool_ksettings_set: Don't discard phy_start_aneg's return

From: Heiner Kallweit <[email-masked]>
Date: Mon, 8 Nov 2021 20:35:53 +0100

On 08.11.2021 20:02, Benedikt Spranger wrote:
> On Mon, 8 Nov 2021 19:01:23 +0100
> Heiner Kallweit <[email-masked]> wrote:
> 
>> If we would like to support PHY's that don't support all MDI modes
>> then supposedly this would require to add ETHTOOL_LINK_MODE bits for
>> the MDI modes. Then we could use the generic mechanism to check the
>> bits in the "supported" bitmap.
> 
> The things are even worse:
> The chip supports only auto-MDIX at Gigabit and force MDI and

The Gigabit part seems to be normal. Gigabit supports neither
forced mode nor forced MDI settings.

> auto-MDIX in 10/100 modes. No force MDIX at all.
> 
> A validation callback from phy_ethtool_ksettings_set() before
> restarting the PHY seems reasonable for me. Something like:
> 
> 	/* Verify the settings we care about. */
> 	if (autoneg != AUTONEG_ENABLE && autoneg != AUTONEG_DISABLE)
> 	        return -EINVAL;
> 
>         if (autoneg == AUTONEG_ENABLE && linkmode_empty(advertising))
> 	        return -EINVAL;
> 
>         if (autoneg == AUTONEG_DISABLE &&
> 	    ((speed != SPEED_1000 &&
> 	      speed != SPEED_100 &&
>               speed != SPEED_10) ||
>              (duplex != DUPLEX_HALF &&
>               duplex != DUPLEX_FULL)))
>                 return -EINVAL;
> 
> 	if (phydev->validate_cmd && phydev->validate_cmd(cmd))
> 		return -EINVAL;
> 
> Thanks
>     Benedikt Spranger
>