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

From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Calvin Johnson <calvin.johnson@oss.nxp.com>
Cc: Grant Likely <grant.likely@arm.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Jeremy Linton <jeremy.linton@arm.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Cristi Sovaiala <cristian.sovaiala@nxp.com>,
	Florin Laurentiu Chiculita <florinlaurentiu.chiculita@nxp.com>,
	Ioana Ciornei <ioana.ciornei@nxp.com>,
	Madalin Bucur <madalin.bucur@oss.nxp.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Marcin Wojtas <mw@semihalf.com>,
	Pieter Jansen Van Vuuren <pieter.jansenvv@bamboosystems.io>,
	Jon <jon@solid-run.com>, Saravana Kannan <saravanak@google.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Laurentiu Tudor <laurentiu.tudor@nxp.com>,
	linux-kernel@vger.kernel.org, linux.cj@gmail.com,
	Diana Madalina Craciun <diana.craciun@nxp.com>,
	netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-acpi@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Ioana Radulescu <ruxandra.radulescu@nxp.com>,
	Jakub Kicinski <kuba@kernel.org>
Subject: Re: [net-next PATCH v5 15/15] net: dpaa2-mac: Add ACPI support for DPAA2 MAC driver
Date: Mon, 8 Feb 2021 16:28:31 +0000	[thread overview]
Message-ID: <20210208162831.GM1463@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210208151244.16338-16-calvin.johnson@oss.nxp.com>

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 <calvin.johnson@oss.nxp.com>

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.

-- 
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