Re: [PATCH 3/9] net: mdio: realtek-rtl9300: Add ports to info structure

[Daniel Golle <daniel@makrotopia.org>]

On Tue, May 19, 2026 at 06:57:41PM +0200, Markus Stockhausen wrote:
> Each Realtek SOC series has different number of MDIO ports.

I don't think the term "MDIO ports" describes it well.

I'd say "switch ports", also because RTL9300_NUM_PORTS includes ports
used for SFP+ cages which aren't going to be (directly) associated
with any MDIO-connected PHY at all.

> Make this configurable by adding a property to the info
> structure. Switch the existing usage of MAX_PORTS to this
> new property where needed.
> 
> Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
> ---
>  drivers/net/mdio/mdio-realtek-rtl9300.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/mdio/mdio-realtek-rtl9300.c b/drivers/net/mdio/mdio-realtek-rtl9300.c
> index 140e6ac51e2b..4533c2f68cab 100644
> --- a/drivers/net/mdio/mdio-realtek-rtl9300.c
> +++ b/drivers/net/mdio/mdio-realtek-rtl9300.c
> @@ -49,9 +49,11 @@
>  #define MAX_SMI_ADDR	0x1f
>  
>  #define RTL9300_NUM_BUSES		4
> +#define RTL9300_NUM_PORTS		28
>  
>  struct rtl_mdio_info {
>  	u8 num_buses;
> +	u8 num_ports;
>  };
>  
>  struct rtl_mdio_priv {
> @@ -78,7 +80,7 @@ static int rtl_mdio_phy_to_port(struct mii_bus *bus, int phy_id)
>  
>  	priv = chan->priv;
>  
> -	for_each_set_bit(i, priv->valid_ports, MAX_PORTS)
> +	for_each_set_bit(i, priv->valid_ports, priv->info->num_ports)
>  		if (priv->smi_bus[i] == chan->mdio_bus &&
>  		    priv->smi_addr[i] == phy_id)
>  			return i;
> @@ -323,7 +325,7 @@ static int rtl9300_mdiobus_init(struct rtl_mdio_priv *priv)
>  	int i, err;
>  
>  	/* Associate the port with the SMI interface and PHY */
> -	for_each_set_bit(i, priv->valid_ports, MAX_PORTS) {
> +	for_each_set_bit(i, priv->valid_ports, priv->info->num_ports) {
>  		int pos;
>  
>  		pos = (i % 6) * 5;
> @@ -444,7 +446,7 @@ static int rtl_mdiobus_map_ports(struct device *dev)
>  		if (err)
>  			return err;
>  
> -		if (pn >= MAX_PORTS)
> +		if (pn >= priv->info->num_ports)
>  			return dev_err_probe(dev, -EINVAL, "illegal port number %d\n", pn);
>  
>  		if (test_bit(pn, priv->valid_ports))
> @@ -509,6 +511,7 @@ static int rtl_mdiobus_probe(struct platform_device *pdev)
>  
>  static const struct rtl_mdio_info rtl9300_mdio_info = {
>  	.num_buses = RTL9300_NUM_BUSES,
> +	.num_ports = RTL9300_NUM_PORTS,
>  };
>  
>  static const struct of_device_id rtl_mdio_ids[] = {
> -- 
> 2.54.0
>