Re: [PATCH 2/2] net: dsa: lantiq_gswip: Fix GSWIP_MII_CFG(p) register access

[Hauke Mehrtens]

On 1/3/21 2:25 AM, Martin Blumenstingl wrote:
> There is one GSWIP_MII_CFG register for each switch-port except the CPU
> port. The register offset for the first port is 0x0, 0x02 for the
> second, 0x04 for the third and so on.
>
> Update the driver to not only restrict the GSWIP_MII_CFG registers to
> ports 0, 1 and 5. Handle ports 0..5 instead but skip the CPU port. This
> means we are not overwriting the configuration for the third port (port
> two since we start counting from zero) with the settings for the sixth
> port (with number five) anymore.
>
> The GSWIP_MII_PCDU(p) registers are not updated because there's really
> only three (one for each of the following ports: 0, 1, 5).
>
> Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

Acked-by: Hauke Mehrtens <hauke@xxxxxxxxxx>

> ---
>   drivers/net/dsa/lantiq_gswip.c | 23 ++++++-----------------
>   1 file changed, 6 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/dsa/lantiq_gswip.c b/drivers/net/dsa/lantiq_gswip.c
> index 5d378c8026f0..4b36d89bec06 100644
> --- a/drivers/net/dsa/lantiq_gswip.c
> +++ b/drivers/net/dsa/lantiq_gswip.c
> @@ -92,9 +92,7 @@
>   					 GSWIP_MDIO_PHY_FDUP_MASK)
>   
>   /* GSWIP MII Registers */
> -#define GSWIP_MII_CFG0			0x00
> -#define GSWIP_MII_CFG1			0x02
> -#define GSWIP_MII_CFG5			0x04
> +#define GSWIP_MII_CFGp(p)		(0x2 * (p))
>   #define  GSWIP_MII_CFG_EN		BIT(14)
>   #define  GSWIP_MII_CFG_LDCLKDIS		BIT(12)
>   #define  GSWIP_MII_CFG_MODE_MIIP	0x0
> @@ -392,17 +390,9 @@ static void gswip_mii_mask(struct gswip_priv *priv, u32 clear, u32 set,
>   static void gswip_mii_mask_cfg(struct gswip_priv *priv, u32 clear, u32 set,
>   			       int port)
>   {
> -	switch (port) {
> -	case 0:
> -		gswip_mii_mask(priv, clear, set, GSWIP_MII_CFG0);
> -		break;
> -	case 1:
> -		gswip_mii_mask(priv, clear, set, GSWIP_MII_CFG1);
> -		break;
> -	case 5:
> -		gswip_mii_mask(priv, clear, set, GSWIP_MII_CFG5);
> -		break;
> -	}
> +	/* There's no MII_CFG register for the CPU port */
> +	if (!dsa_is_cpu_port(priv->ds, port))
> +		gswip_mii_mask(priv, clear, set, GSWIP_MII_CFGp(port));
>   }
>   
>   static void gswip_mii_mask_pcdu(struct gswip_priv *priv, u32 clear, u32 set,
> @@ -822,9 +812,8 @@ static int gswip_setup(struct dsa_switch *ds)
>   	gswip_mdio_mask(priv, 0xff, 0x09, GSWIP_MDIO_MDC_CFG1);
>   
>   	/* Disable the xMII link */
> -	gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, 0);
> -	gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, 1);
> -	gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, 5);
> +	for (i = 0; i < priv->hw_info->max_ports; i++)
> +		gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, i);
>   
>   	/* enable special tag insertion on cpu port */
>   	gswip_switch_mask(priv, 0, GSWIP_FDMA_PCTRL_STEN,