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

From: Ansuel Smith <ansuelsmth@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH net-next v3 06/20] net: dsa: qca8k: handle error with qca8k_write operation
Date: Wed, 5 May 2021 02:47:25 +0200	[thread overview]
Message-ID: <YJHrHV+kSmNxf1GD@Ansuel-xps.localdomain> (raw)
In-Reply-To: <YJHptHS8eN2gGaRd@lunn.ch>

On Wed, May 05, 2021 at 02:41:24AM +0200, Andrew Lunn wrote:
> > -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.
>

I notice that in the driver we use pr function so I assumed this was the
correct way to report errors with a dsa driver. Will change that.

>      Andrew