[PATCH net 1/1] net: stmmac: check fwnode for phy device before scanning for phy

[Russell King (Oracle)]

On Wed, Apr 05, 2023 at 05:39:45PM +0800, Michael Sit Wei Hong wrote:
> Some DT devices already have phy device configured in the DT/ACPI.
> Current implementation scans for a phy unconditionally even though
> there is a phy listed in the DT/ACPI and already attached.
> 
> We should check the fwnode if there is any phy device listed in
> fwnode and decide whether to scan for a phy to attach to.y
> 
> Reported-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>

Suggested-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>

> Fixes: fe2cfbc96803 ("net: stmmac: check if MAC needs to attach to a PHY")
> Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit at intel.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index d41a5f92aee7..7ca9be7bec06 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1134,22 +1134,26 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
>  static int stmmac_init_phy(struct net_device *dev)
>  {
>  	struct stmmac_priv *priv = netdev_priv(dev);
> +	struct fwnode_handle *phy_fwnode;
>  	struct fwnode_handle *fwnode;
> -	bool phy_needed;
>  	int ret;
>  
> +	if (!phylink_expects_phy(priv->phylink))
> +		return 0;
> +
>  	fwnode = of_fwnode_handle(priv->plat->phylink_node);
>  	if (!fwnode)
>  		fwnode = dev_fwnode(priv->device);
>  
>  	if (fwnode)
> -		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
> +		phy_fwnode = fwnode_get_phy_node(fwnode);
> +	else
> +		phy_fwnode = NULL;
>  
> -	phy_needed = phylink_expects_phy(priv->phylink);
>  	/* Some DT bindings do not set-up the PHY handle. Let's try to
>  	 * manually parse it
>  	 */
> -	if (!fwnode || phy_needed || ret) {
> +	if (!phy_fwnode || IS_ERR(phy_fwnode)) {
>  		int addr = priv->plat->phy_addr;
>  		struct phy_device *phydev;
>  
> @@ -1165,6 +1169,9 @@ static int stmmac_init_phy(struct net_device *dev)
>  		}
>  
>  		ret = phylink_connect_phy(priv->phylink, phydev);
> +	} else {
> +		fwnode_handle_put(phy_fwnode);
> +		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
>  	}
>  
>  	if (!priv->plat->pmt) {

LGTM, thanks for taking on board my suggestion.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!