Re: [PATCH v2 2/7] net: phy: micrel: KSZ8081 & KSZ9031: add loopback support

[Florian Fainelli <f.fainelli@gmail.com>]

On 4/15/2021 6:07 AM, Oleksij Rempel wrote:
> PHY loopback is needed for the ethernet controller self test support.
> This PHY was tested with the generic net sefltest in combination with
> FEC ethernet controller and SJA1105 switch.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  drivers/net/phy/micrel.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index a14a00328fa3..26066b1e02e5 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -1311,6 +1311,7 @@ static struct phy_driver ksphy_driver[] = {
>  	.get_stats	= kszphy_get_stats,
>  	.suspend	= kszphy_suspend,
>  	.resume		= kszphy_resume,
> +	.set_loopback	= genphy_loopback,

The generic loopback is really generic and is defined by the 802.3
standard, we should just mandate that drivers implement a custom
loopback if the generic one cannot work. I would change the PHY library
to do something like this:

if (phydev->drv->set_loopback)
	ret = phydev->drv->set_loopback(phydev, ...)
else
	ret = genphy_loopback(phydev, ...)

This would enable many more drivers than that we currently have today.

>  }, {
>  	.phy_id		= PHY_ID_KSZ8061,
>  	.name		= "Micrel KSZ8061",
> @@ -1356,6 +1357,7 @@ static struct phy_driver ksphy_driver[] = {
>  	.get_stats	= kszphy_get_stats,
>  	.suspend	= genphy_suspend,
>  	.resume		= kszphy_resume,
> +	.set_loopback	= genphy_loopback,
>  }, {
>  	.phy_id		= PHY_ID_LAN8814,
>  	.phy_id_mask	= MICREL_PHY_ID_MASK,
> 

-- 
Florian