Subject: Re: [net-next PATCH v5 15/15] net: dpaa2-mac: Add ACPI support for DPAA2 MAC driver

From: Russell King - ARM Linux admin <[email-masked]>
Date: Mon, 8 Feb 2021 16:28:31 +0000

On Mon, Feb 08, 2021 at 08:42:44PM +0530, Calvin Johnson wrote:
> Modify dpaa2_mac_connect() to support ACPI along with DT.
> Modify dpaa2_mac_get_node() to get the dpmac fwnode from either
> DT or ACPI.
> 
> Replace of_get_phy_mode with fwnode_get_phy_mode to get
> phy-mode for a dpmac_node.
> 
> Use helper function phylink_fwnode_phy_connect() to find phy_dev and
> connect to mac->phylink.
> 
> Signed-off-by: Calvin Johnson <[email-masked]>

I don't think this does the full job.

>  static int dpaa2_pcs_create(struct dpaa2_mac *mac,
> -			    struct device_node *dpmac_node, int id)
> +			    struct fwnode_handle *dpmac_node,
> +			    int id)
>  {
>  	struct mdio_device *mdiodev;
> -	struct device_node *node;
> +	struct fwnode_handle *node;
>  
> -	node = of_parse_phandle(dpmac_node, "pcs-handle", 0);
> -	if (!node) {
> +	node = fwnode_find_reference(dpmac_node, "pcs-handle", 0);
> +	if (IS_ERR(node)) {
>  		/* do not error out on old DTS files */
>  		netdev_warn(mac->net_dev, "pcs-handle node not found\n");
>  		return 0;
>  	}
>  
> -	if (!of_device_is_available(node)) {
> +	if (!of_device_is_available(to_of_node(node))) {

If "node" is an ACPI node, then to_of_node() returns NULL, and
of_device_is_available(NULL) is false. So, if we're using ACPI
and we enter this path, we will always hit the error below:

>  		netdev_err(mac->net_dev, "pcs-handle node not available\n");
> -		of_node_put(node);
> +		of_node_put(to_of_node(node));
>  		return -ENODEV;
>  	}

> @@ -306,7 +321,7 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>  	 * error out if the interface mode requests them and there is no PHY
>  	 * to act upon them
>  	 */
> -	if (of_phy_is_fixed_link(dpmac_node) &&
> +	if (of_phy_is_fixed_link(to_of_node(dpmac_node)) &&

If "dpmac_node" is an ACPI node, to_of_node() will return NULL, and
of_phy_is_fixed_link() will oops.

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