Subject: Re: [PATCH NET V4 1/2] net: phy: Add phy loopback support in net phy framework

From: Andrew Lunn <[email-masked]>
Date: Sat, 24 Jun 2017 15:44:36 +0200

> @@ -1087,7 +1087,7 @@ int phy_suspend(struct phy_device *phydev)
>  {
>  	struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
>  	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
> -	int ret = 0;
> +	int ret = -EOPNOTSUPP;
>  
>  	/* If the device has WOL enabled, we cannot suspend the PHY */
>  	phy_ethtool_get_wol(phydev, &wol);
> @@ -1109,7 +1109,7 @@ int phy_suspend(struct phy_device *phydev)
>  int phy_resume(struct phy_device *phydev)
>  {
>  	struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
> -	int ret = 0;
> +	int ret = -EOPNOTSUPP;
>  
>  	if (phydev->drv && phydrv->resume)
>  		ret = phydrv->resume(phydev);
> @@ -1123,6 +1123,39 @@ int phy_resume(struct phy_device *phydev)
>  }

These changes should be in a separate patch, since they have nothing
to do with loopback. You want lots of small patches, making them
easier to both describe the why it is needed, and easier to review.

What are the implications of this change? Are you sure the power core
code does not understand EOPNOTSUPP as being a real error?

>  EXPORT_SYMBOL(phy_resume);
>  
> +int phy_loopback(struct phy_device *phydev, bool enable)
> +{
> +	struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
> +	int ret = 0;
> +
> +	mutex_lock(&phydev->lock);
> +
> +	if (enable && phydev->loopback_enabled) {
> +		ret = -EBUSY;
> +		goto out;
> +	}
> +
> +	if (!enable && !phydev->loopback_enabled) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (phydev->drv && phydrv->set_loopback)
> +		ret = phydrv->set_loopback(phydev, enable);
> +	else
> +		ret = -EOPNOTSUPP;
> +
> +	if (ret)
> +		goto out;
> +
> +	phydev->loopback_enabled = enable;
> +
> +out:
> +	mutex_unlock(&phydev->lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL(phy_loopback);

This looks good now.

     Andrew