[PATCH 8/11] drivers/net/wireless/libertas: Move a dereference below a NULL test

[PATCH 8/11] drivers/net/wireless/libertas: Move a dereference below a NULL test

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

In each case, if the NULL test is necessary, then the dereference should be
moved below the NULL test.  I have also taken advantage of the availability
of the value of priv->dev in the subsequent calls to netif_stop_queue and
netif_carrier_off.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E
      when != i
  if (E == NULL) S
+ i = E->fld;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 drivers/net/wireless/libertas/main.c           |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
index 73dc8c7..91c89da 100644
--- a/drivers/net/wireless/libertas/main.c
+++ b/drivers/net/wireless/libertas/main.c
@@ -1311,7 +1311,7 @@ EXPORT_SYMBOL_GPL(lbs_start_card);
 
 void lbs_stop_card(struct lbs_private *priv)
 {
-	struct net_device *dev = priv->dev;
+	struct net_device *dev;
 	struct cmd_ctrl_node *cmdnode;
 	unsigned long flags;
 
@@ -1319,9 +1319,10 @@ void lbs_stop_card(struct lbs_private *priv)
 
 	if (!priv)
 		goto out;
+	dev = priv->dev;
 
-	netif_stop_queue(priv->dev);
-	netif_carrier_off(priv->dev);
+	netif_stop_queue(dev);
+	netif_carrier_off(dev);
 
 	lbs_debugfs_remove_one(priv);
 	if (priv->mesh_tlv) {

Re: [PATCH 8/11] drivers/net/wireless/libertas: Move a dereference below a NULL test

[Dan Williams]

On Tue, 2008-12-16 at 16:14 +0100, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> In each case, if the NULL test is necessary, then the dereference should be
> moved below the NULL test.  I have also taken advantage of the availability
> of the value of priv->dev in the subsequent calls to netif_stop_queue and
> netif_carrier_off.
> 
> The semantic patch that makes this change is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @@
> type T;
> expression E;
> identifier i,fld;
> statement S;
> @@
> 
> - T i = E->fld;
> + T i;
>   ... when != E
>       when != i
>   if (E == NULL) S
> + i = E->fld;
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Acked-by: Dan Williams <dcbw@redhat.com>

> ---
>  drivers/net/wireless/libertas/main.c           |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
> index 73dc8c7..91c89da 100644
> --- a/drivers/net/wireless/libertas/main.c
> +++ b/drivers/net/wireless/libertas/main.c
> @@ -1311,7 +1311,7 @@ EXPORT_SYMBOL_GPL(lbs_start_card);
>  
>  void lbs_stop_card(struct lbs_private *priv)
>  {
> -	struct net_device *dev = priv->dev;
> +	struct net_device *dev;
>  	struct cmd_ctrl_node *cmdnode;
>  	unsigned long flags;
>  
> @@ -1319,9 +1319,10 @@ void lbs_stop_card(struct lbs_private *priv)
>  
>  	if (!priv)
>  		goto out;
> +	dev = priv->dev;
>  
> -	netif_stop_queue(priv->dev);
> -	netif_carrier_off(priv->dev);
> +	netif_stop_queue(dev);
> +	netif_carrier_off(dev);
>  
>  	lbs_debugfs_remove_one(priv);
>  	if (priv->mesh_tlv) {