Re: [PATCH net-next] net: dsa: mt7530: fix support for MT7531BE

[Jesse Brandeburg]

On 4/10/2023 5:11 PM, Daniel Golle wrote:
> There are two variants of the MT7531 switch IC which got different
> features (and pins) regarding port 5:
>  * MT7531AE: SGMII/1000Base-X/2500Base-X SerDes
>  * MT7531BE: RGMII
> 
> Moving the creation of the SerDes PCS from mt753x_setup to mt7530_probe
> with commit 6de285229773 ("net: dsa: mt7530: move SGMII PCS creation to
> mt7530_probe function") works fine for MT7531AE which got two instances
> of mtk-pcs-lynxi, however, MT7531BE requires mt7531_pll_setup to setup
> clocks before the single PCS on port 6 (usually used as CPU port)
> starts to work and hence the PCS creation failed on MT7531BE.
> 
> Fix this by introducing a pointer to mt7531_create_sgmii function in
> struct mt7530_priv and call it again at the end of mt753x_setup like it
> was before commit 6de285229773 ("net: dsa: mt7530: move SGMII PCS
> creation to mt7530_probe function").
> 
> Fixes: 6de285229773 ("net: dsa: mt7530: move SGMII PCS creation to mt7530_probe function")
> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> ---
>  drivers/net/dsa/mt7530-mdio.c | 14 +++++++-------
>  drivers/net/dsa/mt7530.c      |  6 ++++++
>  drivers/net/dsa/mt7530.h      |  4 ++++
>  3 files changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/dsa/mt7530-mdio.c b/drivers/net/dsa/mt7530-mdio.c
> index 34a547b88e497..f17eab67d15fa 100644
> --- a/drivers/net/dsa/mt7530-mdio.c
> +++ b/drivers/net/dsa/mt7530-mdio.c
> @@ -81,14 +81,17 @@ static const struct regmap_bus mt7530_regmap_bus = {
>  };
>  
>  static int
> -mt7531_create_sgmii(struct mt7530_priv *priv)
> +mt7531_create_sgmii(struct mt7530_priv *priv, bool dual_sgmii)
>  {
>  	struct regmap_config *mt7531_pcs_config[2];

[1] use = {};

>  	struct phylink_pcs *pcs;
>  	struct regmap *regmap;
>  	int i, ret = 0;
>  
> -	for (i = 0; i < 2; i++) {
> +	/* MT7531AE has two SGMII units for port 5 and port 6
> +	 * MT7531BE has only one SGMII unit for port 6
> +	 */
> +	for (i = dual_sgmii ? 0 : 1; i < 2; i++) {
>  		mt7531_pcs_config[i] = devm_kzalloc(priv->dev,

hm, I don't like this, you're no longer initializing array[0] if
dual_sgmii is set. This seems like a recipe for disaster.

you could initialize the array to NULL above when allocating this on the
stack? [1]


>  						    sizeof(struct regmap_config),
>  						    GFP_KERNEL);
> @@ -208,11 +211,8 @@ mt7530_probe(struct mdio_device *mdiodev)
>  	if (IS_ERR(priv->regmap))
>  		return PTR_ERR(priv->regmap);
>  
> -	if (priv->id == ID_MT7531) {
> -		ret = mt7531_create_sgmii(priv);
> -		if (ret)
> -			return ret;
> -	}
> +	if (priv->id == ID_MT7531)
> +		priv->create_sgmii = mt7531_create_sgmii;
>  
>  	return dsa_register_switch(priv->ds);
>  }
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index e4bb5037d3525..c680873819b01 100644
> --- a/drivers/net/dsa/mt7530.c
> +++ b/drivers/net/dsa/mt7530.c
> @@ -3018,6 +3018,12 @@ mt753x_setup(struct dsa_switch *ds)
>  	if (ret && priv->irq)
>  		mt7530_free_irq_common(priv);
>  
> +	if (priv->create_sgmii) {
> +		ret = priv->create_sgmii(priv, mt7531_dual_sgmii_supported(priv));
> +		if (ret && priv->irq)
> +			mt7530_free_irq(priv);
> +	}
> +
>  	return ret;
>  }
>  
> diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
> index 01db5c9724fa8..6e89578b4de02 100644
> --- a/drivers/net/dsa/mt7530.h
> +++ b/drivers/net/dsa/mt7530.h
> @@ -752,6 +752,8 @@ struct mt753x_info {
>   * @irq:		IRQ number of the switch
>   * @irq_domain:		IRQ domain of the switch irq_chip
>   * @irq_enable:		IRQ enable bits, synced to SYS_INT_EN
> + *

no extra blank line needed here.

> + * @create_sgmii:	Pointer to function creating SGMII PCS instance(s)
>   */
>  struct mt7530_priv {
>  	struct device		*dev;
> @@ -778,6 +780,8 @@ struct mt7530_priv {
>  	int irq;
>  	struct irq_domain *irq_domain;
>  	u32 irq_enable;
> +
> +	int (*create_sgmii)(struct mt7530_priv *priv, bool dual_sgmii);
>  };
>  
>  struct mt7530_hw_vlan_entry {