linux-kernel - RE: [PATCH 2/5] net: emaclite: Balance braces in else statement

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Message-ID: <DM6PR02MB436134273D962B3FF3242723C7700@DM6PR02MB4361.namprd02.prod.outlook.com>
Date:   Tue, 19 Jun 2018 05:42:11 +0000
From:   Radhey Shyam Pandey <radheys@...inx.com>
To:     Joe Perches <joe@...ches.com>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "andrew@...n.ch" <andrew@...n.ch>,
        Michal Simek <michals@...inx.com>
CC:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 2/5] net: emaclite: Balance braces in else statement

> -----Original Message-----
> From: Joe Perches [mailto:joe@...ches.com]
> Sent: Monday, June 18, 2018 9:33 PM
> To: Radhey Shyam Pandey <radheys@...inx.com>; davem@...emloft.net;
> andrew@...n.ch; Michal Simek <michals@...inx.com>
> Cc: netdev@...r.kernel.org; linux-arm-kernel@...ts.infradead.org; linux-
> kernel@...r.kernel.org
> Subject: Re: [PATCH 2/5] net: emaclite: Balance braces in else statement
> 
> On Mon, 2018-06-18 at 17:20 +0530, Radhey Shyam Pandey wrote:
> > Remove else as it is not required with if doing a return.
> > Fixes below checkpatch warning.
> 
> > WARNING: else is not generally useful after a break or return
> 
> checkpatch is stupid and doesn't understand code flow.
> Always try to improve code flow instead of merely
> following brainless instructions from a script.
> 
> So:
> 
> > diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> []
> > @@ -569,13 +569,11 @@ static void xemaclite_tx_handler(struct net_device
> *dev)
> >  					(u8 *) lp->deferred_skb->data,
> >  					lp->deferred_skb->len) != 0)
> >  			return;
> > -		else {
> > -			dev->stats.tx_bytes += lp->deferred_skb->len;
> > -			dev_kfree_skb_irq(lp->deferred_skb);
> > -			lp->deferred_skb = NULL;
> > -			netif_trans_update(dev); /* prevent tx timeout */
> > -			netif_wake_queue(dev);
> > -		}
> > +		dev->stats.tx_bytes += lp->deferred_skb->len;
> > +		dev_kfree_skb_irq(lp->deferred_skb);
> > +		lp->deferred_skb = NULL;
> > +		netif_trans_update(dev); /* prevent tx timeout */
> > +		netif_wake_queue(dev);
> >  	}
> >  }
> 
> If you really want to redo this function, perhaps something like:
Thanks for the review. Yes, In v2 I will refactor the code to have
failure path return early.

> 
> static void xemaclite_tx_handler(struct net_device *dev)
> {
> 	struct net_local *lp = netdev_priv(dev);
> 
> 	dev->stats.tx_packets++;
> 
> 	if (!lp->deferred_skb)
> 		return;
> 
> 	if (xemaclite_send_data(lp, (u8 *)lp->deferred_skb->data,
> 				lp->deferred_skb->len))
> 		return;
> 
> 	dev->stats.tx_bytes += lp->deferred_skb->len;
> 	dev_kfree_skb_irq(lp->deferred_skb);
> 	lp->deferred_skb = NULL;
> 	netif_trans_update(dev); /* prevent tx timeout */
> 	netif_wake_queue(dev);
> }
> 
> > @@ -1052,13 +1050,13 @@ static bool get_bool(struct platform_device
> *ofdev, const char *s)
> >  {
> >  	u32 *p = (u32 *)of_get_property(ofdev->dev.of_node, s, NULL);
> >
> > -	if (p) {
> > +	if (p)
> >  		return (bool)*p;
> > -	} else {
> > -		dev_warn(&ofdev->dev, "Parameter %s not found,"
> > +
> > +	dev_warn(&ofdev->dev, "Parameter %s not found,"
> >  			"defaulting to false\n", s);
> > -		return false;
> > -	}
> > +
> > +	return false;
> >  }
> 
> And this function has backward logic as the failure paths
> are the ones that should return early or use a goto.
> 
> Perhaps something like:
Yes, will change it. 

> 
> static bool get_bool(struct platform_device *ofdev, const char *s)
> {
> 	u32 *p = (u32 *)of_get_property(ofdev->dev.of_node, s, NULL);
> 
> 	if (!p) {
> 		dev_warn(&ofdev->dev,
> 			 "Parameter '%s' not found, defaulting to false\n", s);
> 		return false;
> 	}
> 
> 	return *p;
> }