Subject: Re: [RFC PATCH net-next v3 06/20] net: dsa: qca8k: handle error with qca8k_write operation

From: Andrew Lunn <[email-masked]>
Date: Wed, 5 May 2021 02:41:24 +0200

> -static void
> +static int
>  qca8k_write(struct qca8k_priv *priv, u32 reg, u32 val)
>  {
> +	struct mii_bus *bus = priv->bus;
>  	u16 r1, r2, page;
>  	int ret;
>  
>  	qca8k_split_addr(reg, &r1, &r2, &page);
>  
> -	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
> +	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
>  
>  	ret = qca8k_set_page(priv->bus, page);
>  	if (ret < 0)
> @@ -183,6 +184,7 @@ qca8k_write(struct qca8k_priv *priv, u32 reg, u32 val)
>  
>  exit:
>  	mutex_unlock(&priv->bus->mdio_lock);
> +	return ret;
>  }

Same comment as read. Maybe put this and the other similar change into one patch.

> @@ -636,7 +660,9 @@ qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum)
>  	      QCA8K_MDIO_MASTER_READ | QCA8K_MDIO_MASTER_PHY_ADDR(phy) |
>  	      QCA8K_MDIO_MASTER_REG_ADDR(regnum);
>  
> -	qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val);
> +	ret = qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val);
> +	if (ret)
> +		return ret;
>  
>  	if (qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
>  			    QCA8K_MDIO_MASTER_BUSY))
> @@ -767,12 +793,18 @@ qca8k_setup(struct dsa_switch *ds)
>  		      QCA8K_GLOBAL_FW_CTRL0_CPU_PORT_EN);
>  
>  	/* Enable MIB counters */
> -	qca8k_mib_init(priv);
> +	ret = qca8k_mib_init(priv);
> +	if (ret)
> +		pr_warn("mib init failed");

Please use dev_warn().

>  
>  	/* Enable QCA header mode on the cpu port */
> -	qca8k_write(priv, QCA8K_REG_PORT_HDR_CTRL(QCA8K_CPU_PORT),
> -		    QCA8K_PORT_HDR_CTRL_ALL << QCA8K_PORT_HDR_CTRL_TX_S |
> -		    QCA8K_PORT_HDR_CTRL_ALL << QCA8K_PORT_HDR_CTRL_RX_S);
> +	ret = qca8k_write(priv, QCA8K_REG_PORT_HDR_CTRL(QCA8K_CPU_PORT),
> +			  QCA8K_PORT_HDR_CTRL_ALL << QCA8K_PORT_HDR_CTRL_TX_S |
> +			  QCA8K_PORT_HDR_CTRL_ALL << QCA8K_PORT_HDR_CTRL_RX_S);
> +	if (ret) {
> +		pr_err("failed enabling QCA header mode");

dev_err()

In general, always use dev_err(), dev_warn(), dev_info() etc, so we
know which device returned an error.

     Andrew