[PATCH] arch/powerpc/platforms/powermac/pic.c: move of_node_put

[PATCH] arch/powerpc/platforms/powermac/pic.c: move of_node_put

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

It seems better to dereference master before decrementing the reference
count rather than afterwards.

The problem was found using the following semantic match:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
expression n,E;
identifier fld;
iterator I;
statement S;
@@

* of_node_put(n)
... when != n = E
    when != I(n,...) S
* n->fld
// </smpl>

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

---

 arch/powerpc/platforms/powermac/pic.c          |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index 6d149ae..d17aa2b 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -395,10 +395,10 @@ static void __init pmac_pic_probe_oldstyle(void)
 	if (max_real_irqs > 32)
 		pmac_irq_hw[i++] = (volatile struct pmac_irq_hw __iomem *)
 			(addr + 0x10);
-	of_node_put(master);
 
 	printk(KERN_INFO "irq: Found primary Apple PIC %s for %d irqs\n",
 	       master->full_name, max_real_irqs);
+	of_node_put(master);
 
 	/* Map interrupts of cascaded controller */
 	if (slave && !of_address_to_resource(slave, 0, &r)) {

Re: [PATCH] arch/powerpc/platforms/powermac/pic.c: move of_node_put

[Benjamin Herrenschmidt]

On Sun, 2008-09-21 at 13:01 +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> It seems better to dereference master before decrementing the reference
> count rather than afterwards.
> 
> The problem was found using the following semantic match:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> expression n,E;
> identifier fld;
> iterator I;
> statement S;
> @@
> 
> * of_node_put(n)
> ... when != n = E
>     when != I(n,...) S
> * n->fld
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Ack.

No big deal, tho, those nodes are never going to go away :-)

Cheers,
Ben.

> ---
> 
>  arch/powerpc/platforms/powermac/pic.c          |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
> index 6d149ae..d17aa2b 100644
> --- a/arch/powerpc/platforms/powermac/pic.c
> +++ b/arch/powerpc/platforms/powermac/pic.c
> @@ -395,10 +395,10 @@ static void __init pmac_pic_probe_oldstyle(void)
>  	if (max_real_irqs > 32)
>  		pmac_irq_hw[i++] = (volatile struct pmac_irq_hw __iomem *)
>  			(addr + 0x10);
> -	of_node_put(master);
>  
>  	printk(KERN_INFO "irq: Found primary Apple PIC %s for %d irqs\n",
>  	       master->full_name, max_real_irqs);
> +	of_node_put(master);
>  
>  	/* Map interrupts of cascaded controller */
>  	if (slave && !of_address_to_resource(slave, 0, &r)) {