Re: [RFC PATCH v3 net-next 2/6] net: phylink: introduce a generic method for querying PHY in-band autoneg capability

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Wed, Sep 22, 2021 at 09:14:42PM +0300, Vladimir Oltean wrote:
> +static unsigned int phylink_fixup_inband_aneg(struct phylink *pl,
> +					      struct phy_device *phy,
> +					      unsigned int mode)
> +{
> +	int ret;
> +
> +	ret = phy_validate_inband_aneg(phy, pl->link_interface);
> +	if (ret == PHY_INBAND_ANEG_UNKNOWN) {
> +		phylink_dbg(pl,
> +			    "PHY driver does not report in-band autoneg capability, assuming %s\n",
> +			    phylink_autoneg_inband(mode) ? "true" : "false");
> +
> +		return mode;
> +	}
> +
> +	if (phylink_autoneg_inband(mode) && !(ret & PHY_INBAND_ANEG_ON)) {
> +		phylink_err(pl,
> +			    "Requested in-band autoneg but driver does not support this, disabling it.\n");

If we add support to the BCM84881 driver to work with
phy_validate_inband_aneg(), then this will always return
PHY_INBAND_ANEG_OFF and never PHY_INBAND_ANEG_ON. Consequently,
this will always produce this "error". It is not an error in the
SFP case, but it is if firmware is misconfigured.

So, this needs better handling - we should not be issuing an error-
level kernel message for something that is "normal".

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!