Subject: Re: [net-next PATCH v2 3/3] phylink: Introduce phylink_fwnode_phy_connect()

From: Russell King - ARM Linux admin <[email-masked]>
Date: Mon, 27 Apr 2020 14:56:23 +0100

On Mon, Apr 27, 2020 at 06:54:09PM +0530, Calvin Johnson wrote:
> Define phylink_fwnode_phy_connect() to connect phy specified by
> a fwnode to a phylink instance. Additionally,
> phylink_device_phy_connect() is defined to connect phy specified
> by a device to a phylink instance.
> 
> Signed-off-by: Calvin Johnson <[email-masked]>
> ---
> 
> Changes in v2:
>   replace of_ and acpi_ code with generic fwnode to get phy-handle.
> 
>  drivers/net/phy/phylink.c | 68 +++++++++++++++++++++++++++++++++++++++
>  include/linux/phylink.h   |  6 ++++
>  2 files changed, 74 insertions(+)
> 
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index 0f23bec431c1..5eab1eadded7 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -961,6 +961,74 @@ int phylink_connect_phy(struct phylink *pl, struct phy_device *phy)
>  }
>  EXPORT_SYMBOL_GPL(phylink_connect_phy);
>  
> +/**
> + * phylink_fwnode_phy_connect() - connect the PHY specified in the fwnode.
> + * @pl: a pointer to a &struct phylink returned from phylink_create()
> + * @fwnode: a pointer to a &struct fwnode_handle.
> + * @flags: PHY-specific flags to communicate to the PHY device driver
> + *
> + * Connect the phy specified @fwnode to the phylink instance specified
> + * by @pl. Actions specified in phylink_connect_phy() will be
> + * performed.
> + *
> + * Returns 0 on success or a negative errno.
> + */
> +int phylink_fwnode_phy_connect(struct phylink *pl,
> +			       struct fwnode_handle *fwnode,
> +			       u32 flags)
> +{
> +	struct fwnode_handle *phy_fwnode;
> +	struct phy_device *phy_dev;
> +	int ret = 0;
> +
> +	/* Fixed links and 802.3z are handled without needing a PHY */
> +	if (pl->cfg_link_an_mode == MLO_AN_FIXED ||
> +	    (pl->cfg_link_an_mode == MLO_AN_INBAND &&
> +	     phy_interface_mode_is_8023z(pl->link_interface)))
> +		return 0;
> +
> +	phy_fwnode = fwnode_get_phy_node(fwnode);
> +	if ((IS_ERR_OR_NULL(phy_fwnode)) && (pl->cfg_link_an_mode == MLO_AN_PHY))

According to your documentation for fwnode_get_phy_node(), it can't
return NULL.  So, use of IS_ERR_OR_NULL() is incorrect here.  Please
also eliminate the unnecessary parens to match the style in the rest
of this file.

> +		return -ENODEV;

If fwnode_get_phy_node() returns an error pointer, shouldn't you be
propagating that error here?

> +
> +	phy_dev = fwnode_phy_find_device(phy_fwnode);
> +	fwnode_handle_put(phy_fwnode);
> +	if (!phy_dev)
> +		return -ENODEV;
> +
> +	ret = phy_attach_direct(pl->netdev, phy_dev, flags,
> +				pl->link_interface);
> +	if (ret)
> +		return ret;
> +
> +	ret = phylink_bringup_phy(pl, phy_dev, pl->link_config.interface);
> +	if (ret)
> +		phy_detach(phy_dev);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(phylink_fwnode_phy_connect);
> +
> +/**
> + * phylink_device_phy_connect() - connect the PHY specified by the device.
> + * @pl: a pointer to a &struct phylink returned from phylink_create()
> + * @dev: a pointer to a &struct device.
> + * @flags: PHY-specific flags to communicate to the PHY device driver
> + *
> + * Connect the phy specified by the device to the phylink instance specified
> + * by @pl. Actions specified in phylink_connect_phy() will be
> + * performed.
> + *
> + * Returns 0 on success or a negative errno.
> + */
> +int phylink_device_phy_connect(struct phylink *pl,
> +			       struct device *dev,
> +			       u32 flags)
> +{
> +	return phylink_fwnode_phy_connect(pl, dev_fwnode(dev), flags);
> +}
> +EXPORT_SYMBOL_GPL(phylink_device_phy_connect);

If this has any users, I think this should be an inline function in
phylink.h - it's just a helper after all.  If it doesn't then it should
just be dropped.

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up