Re: [PATCH] net: macb: Fix mdio child node detection

[Sean Anderson]

On 10/26/21 1:39 PM, Guenter Roeck wrote:
> Commit 4d98bb0d7ec2 ("net: macb: Use mdio child node for MDIO bus if it
> exists") added code to detect if a 'mdio' child node exists to the macb
> driver. Ths added code does, however, not actually check if the child node
> exists, but if the parent node exists. This results in errors such as
>
> macb 10090000.ethernet eth0: Could not attach PHY (-19)
>
> if there is no 'mdio' child node. Fix the code to actually check for
> the child node.
>
> Fixes: 4d98bb0d7ec2 ("net: macb: Use mdio child node for MDIO bus if it exists")
> Cc: Sean Anderson <sean.anderson@xxxxxxxx>
> Cc: Andrew Lunn <andrew@xxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
>   drivers/net/ethernet/cadence/macb_main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 309371abfe23..ffce528aa00e 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -901,7 +901,7 @@ static int macb_mdiobus_register(struct macb *bp)
>   	 * directly under the MAC node
>   	 */
>   	child = of_get_child_by_name(np, "mdio");
> -	if (np) {
> +	if (child) {
>   		int ret = of_mdiobus_register(bp->mii_bus, child);
>   
>   		of_node_put(child);

Thanks for catching this.

Reviewed-by: Sean Anderson <sean.anderson@xxxxxxxx>