Subject: Re: [RFC PATCH net-next v3 07/20] net: dsa: qca8k: handle error with qca8k_rmw operation

From: Andrew Lunn <[email-masked]>
Date: Wed, 5 May 2021 02:46:23 +0200

> -static void
> +static int
>  qca8k_reg_set(struct qca8k_priv *priv, u32 reg, u32 val)
>  {
> -	qca8k_rmw(priv, reg, 0, val);
> +	int ret;
> +
> +	ret = qca8k_rmw(priv, reg, 0, val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;

Maybe return qca8k_rmw(priv, reg, 0, val); ??

> -static void
> +static int
>  qca8k_reg_clear(struct qca8k_priv *priv, u32 reg, u32 val)
>  {
> -	qca8k_rmw(priv, reg, val, 0);
> +	int ret;
> +
> +	ret = qca8k_rmw(priv, reg, val, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
>  }

Maybe return qca8k_rmw(priv, reg, val, 0);

> @@ -1249,17 +1280,20 @@ qca8k_port_bridge_join(struct dsa_switch *ds, int port, struct net_device *br)
>  		/* Add this port to the portvlan mask of the other ports
>  		 * in the bridge
>  		 */
> -		qca8k_reg_set(priv,
> -			      QCA8K_PORT_LOOKUP_CTRL(i),
> -			      BIT(port));
> +		ret = qca8k_reg_set(priv,
> +				    QCA8K_PORT_LOOKUP_CTRL(i),
> +				    BIT(port));
> +		if (ret)
> +			return ret;
>  		if (i != port)
>  			port_mask |= BIT(i);
>  	}
> +
>  	/* Add all other ports to this ports portvlan mask */
> -	qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
> -		  QCA8K_PORT_LOOKUP_MEMBER, port_mask);
> +	ret = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
> +			QCA8K_PORT_LOOKUP_MEMBER, port_mask);
>  
> -	return 0;
> +	return ret < 0 ? ret : 0;

Can this is simplified to 

	return  = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
			    QCA8K_PORT_LOOKUP_MEMBER, port_mask);

> @@ -1396,18 +1430,19 @@ qca8k_port_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering,
>  			  struct netlink_ext_ack *extack)
>  {
>  	struct qca8k_priv *priv = ds->priv;
> +	int ret;
>  
>  	if (vlan_filtering) {
> -		qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
> -			  QCA8K_PORT_LOOKUP_VLAN_MODE,
> -			  QCA8K_PORT_LOOKUP_VLAN_MODE_SECURE);
> +		ret = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
> +				QCA8K_PORT_LOOKUP_VLAN_MODE,
> +				QCA8K_PORT_LOOKUP_VLAN_MODE_SECURE);
>  	} else {
> -		qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
> -			  QCA8K_PORT_LOOKUP_VLAN_MODE,
> -			  QCA8K_PORT_LOOKUP_VLAN_MODE_NONE);
> +		ret = qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
> +				QCA8K_PORT_LOOKUP_VLAN_MODE,
> +				QCA8K_PORT_LOOKUP_VLAN_MODE_NONE);
>  	}
>  
> -	return 0;
> +	return ret < 0 ? ret : 0;

What does qca8k_rmw() actually return?

     Andrew