Re: [PATCH net 1/2] dsa: lan9303: Fix mapping between DSA port number and PHY address

[Michal Kubiak <michal.kubiak@intel.com>]

On Wed, Jul 03, 2024 at 04:57:17PM +0200, Christian Eggers wrote:
> The 'phy' parameter supplied to lan9303_phy_read/_write was sometimes a
> DSA port number and sometimes a PHY address. This isn't a problem as
> long as they are equal.  But if the external phy_addr_sel_strap pin is
> wired to 'high', the PHY addresses change from 0-1-2 to 1-2-3 (CPU,
> slave0, slave1).  In this case, lan9303_phy_read/_write must translate
> between DSA port numbers and the corresponding PHY address.
> 
> Fixes: a1292595e006 ("net: dsa: add new DSA switch driver for the SMSC-LAN9303")
> Signed-off-by: Christian Eggers <ceggers@arri.de>
> ---
>  drivers/net/dsa/lan9303-core.c | 23 ++++++++++-------------
>  1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
> index 02f07b870f10..268949939636 100644
> --- a/drivers/net/dsa/lan9303-core.c
> +++ b/drivers/net/dsa/lan9303-core.c
> @@ -1047,31 +1047,31 @@ static int lan9303_get_sset_count(struct dsa_switch *ds, int port, int sset)
>  	return ARRAY_SIZE(lan9303_mib);
>  }
>  
> -static int lan9303_phy_read(struct dsa_switch *ds, int phy, int regnum)
> +static int lan9303_phy_read(struct dsa_switch *ds, int port, int regnum)
>  {
>  	struct lan9303 *chip = ds->priv;
>  	int phy_base = chip->phy_addr_base;
>  
> -	if (phy == phy_base)
> +	if (port == 0)
>  		return lan9303_virt_phy_reg_read(chip, regnum);
> -	if (phy > phy_base + 2)
> +	if (port > 2)
>  		return -ENODEV;
>  
> -	return chip->ops->phy_read(chip, phy, regnum);
> +	return chip->ops->phy_read(chip, phy_base + port, regnum);
>  }
>  
> -static int lan9303_phy_write(struct dsa_switch *ds, int phy, int regnum,
> +static int lan9303_phy_write(struct dsa_switch *ds, int port, int regnum,
>  			     u16 val)
>  {
>  	struct lan9303 *chip = ds->priv;
>  	int phy_base = chip->phy_addr_base;
>  
> -	if (phy == phy_base)
> +	if (port == 0)
>  		return lan9303_virt_phy_reg_write(chip, regnum, val);
> -	if (phy > phy_base + 2)
> +	if (port > 2)
>  		return -ENODEV;
>  
> -	return chip->ops->phy_write(chip, phy, regnum, val);
> +	return chip->ops->phy_write(chip, phy_base + port, regnum, val);
>  }
>  
>  static int lan9303_port_enable(struct dsa_switch *ds, int port,
> @@ -1099,7 +1099,7 @@ static void lan9303_port_disable(struct dsa_switch *ds, int port)
>  	vlan_vid_del(dsa_port_to_conduit(dp), htons(ETH_P_8021Q), port);
>  
>  	lan9303_disable_processing_port(chip, port);
> -	lan9303_phy_write(ds, chip->phy_addr_base + port, MII_BMCR, BMCR_PDOWN);
> +	lan9303_phy_write(ds, port, MII_BMCR, BMCR_PDOWN);
>  }
>  
>  static int lan9303_port_bridge_join(struct dsa_switch *ds, int port,
> @@ -1374,8 +1374,6 @@ static const struct dsa_switch_ops lan9303_switch_ops = {
>  
>  static int lan9303_register_switch(struct lan9303 *chip)
>  {
> -	int base;
> -
>  	chip->ds = devm_kzalloc(chip->dev, sizeof(*chip->ds), GFP_KERNEL);
>  	if (!chip->ds)
>  		return -ENOMEM;
> @@ -1385,8 +1383,7 @@ static int lan9303_register_switch(struct lan9303 *chip)
>  	chip->ds->priv = chip;
>  	chip->ds->ops = &lan9303_switch_ops;
>  	chip->ds->phylink_mac_ops = &lan9303_phylink_mac_ops;
> -	base = chip->phy_addr_base;
> -	chip->ds->phys_mii_mask = GENMASK(LAN9303_NUM_PORTS - 1 + base, base);
> +	chip->ds->phys_mii_mask = GENMASK(LAN9303_NUM_PORTS - 1, 0);
>  
>  	return dsa_register_switch(chip->ds);
>  }
> -- 
> 2.43.0
> 
> 

The patch looks OK.

Thanks,
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>