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* [PATCH] mfd: avoid two assignments if failures happen in tps65910_i2c_probe
@ 2011-07-13 21:22 Jesper Juhl
  2011-07-15  9:12 ` Graeme Gregory
  2011-07-27  9:52 ` Samuel Ortiz
  0 siblings, 2 replies; 3+ messages in thread
From: Jesper Juhl @ 2011-07-13 21:22 UTC (permalink / raw)
  To: Samuel Ortiz; +Cc: linux-kernel, Graeme Gregory, Jorge Eduardo Candelaria

In drivers/mfd/tps65910.c:tps65910_i2c_probe() there's potential for a
tiny optimization.

We assign to init_data->irq and init_data->irq_base long before we
need them, and there are two potential exits from the function before
they are needed.

Moving the assignments below these two potential exits means we
completely avoid doing them in these two (failure) cases.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 drivers/mfd/tps65910.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

  - compile tested only.
  - patch is on top of the patch in https://lkml.org/lkml/2011/7/5/503 
    which is now in linux-next.

diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
index 7a3eb2d..65e9479 100644
--- a/drivers/mfd/tps65910.c
+++ b/drivers/mfd/tps65910.c
@@ -147,9 +147,6 @@ static int tps65910_i2c_probe(struct i2c_client *i2c,
 	if (init_data == NULL)
 		return -ENOMEM;
 
-	init_data->irq = pmic_plat_data->irq;
-	init_data->irq_base = pmic_plat_data->irq;
-
 	tps65910 = kzalloc(sizeof(struct tps65910), GFP_KERNEL);
 	if (tps65910 == NULL) {
 		kfree(init_data);
@@ -170,6 +167,9 @@ static int tps65910_i2c_probe(struct i2c_client *i2c,
 	if (ret < 0)
 		goto err;
 
+	init_data->irq = pmic_plat_data->irq;
+	init_data->irq_base = pmic_plat_data->irq;
+
 	tps65910_gpio_init(tps65910, pmic_plat_data->gpio_base);
 
 	ret = tps65910_irq_init(tps65910, init_data->irq, init_data);
-- 
1.7.6


-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] mfd: avoid two assignments if failures happen in tps65910_i2c_probe
  2011-07-13 21:22 [PATCH] mfd: avoid two assignments if failures happen in tps65910_i2c_probe Jesper Juhl
@ 2011-07-15  9:12 ` Graeme Gregory
  2011-07-27  9:52 ` Samuel Ortiz
  1 sibling, 0 replies; 3+ messages in thread
From: Graeme Gregory @ 2011-07-15  9:12 UTC (permalink / raw)
  To: Jesper Juhl; +Cc: Samuel Ortiz, linux-kernel, Jorge Eduardo Candelaria

On 07/13/2011 10:22 PM, Jesper Juhl wrote:
> In drivers/mfd/tps65910.c:tps65910_i2c_probe() there's potential for a
> tiny optimization.
>
> We assign to init_data->irq and init_data->irq_base long before we
> need them, and there are two potential exits from the function before
> they are needed.
>
> Moving the assignments below these two potential exits means we
> completely avoid doing them in these two (failure) cases.
>
> Signed-off-by: Jesper Juhl <jj@chaosbits.net>
> ---
>  drivers/mfd/tps65910.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
>
>   - compile tested only.
>   - patch is on top of the patch in https://lkml.org/lkml/2011/7/5/503 
>     which is now in linux-next.
>
> diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
> index 7a3eb2d..65e9479 100644
> --- a/drivers/mfd/tps65910.c
> +++ b/drivers/mfd/tps65910.c
> @@ -147,9 +147,6 @@ static int tps65910_i2c_probe(struct i2c_client *i2c,
>  	if (init_data == NULL)
>  		return -ENOMEM;
>  
> -	init_data->irq = pmic_plat_data->irq;
> -	init_data->irq_base = pmic_plat_data->irq;
> -
>  	tps65910 = kzalloc(sizeof(struct tps65910), GFP_KERNEL);
>  	if (tps65910 == NULL) {
>  		kfree(init_data);
> @@ -170,6 +167,9 @@ static int tps65910_i2c_probe(struct i2c_client *i2c,
>  	if (ret < 0)
>  		goto err;
>  
> +	init_data->irq = pmic_plat_data->irq;
> +	init_data->irq_base = pmic_plat_data->irq;
> +
>  	tps65910_gpio_init(tps65910, pmic_plat_data->gpio_base);
>  
>  	ret = tps65910_irq_init(tps65910, init_data->irq, init_data);
Not sure this form of micro optimisation really buys anything, but the
resulting code does look nicer so.

Acked-by: Graeme Gregory <gg@slimlogic.co.uk>


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] mfd: avoid two assignments if failures happen in tps65910_i2c_probe
  2011-07-13 21:22 [PATCH] mfd: avoid two assignments if failures happen in tps65910_i2c_probe Jesper Juhl
  2011-07-15  9:12 ` Graeme Gregory
@ 2011-07-27  9:52 ` Samuel Ortiz
  1 sibling, 0 replies; 3+ messages in thread
From: Samuel Ortiz @ 2011-07-27  9:52 UTC (permalink / raw)
  To: Jesper Juhl; +Cc: linux-kernel, Graeme Gregory, Jorge Eduardo Candelaria

Hi Jesper,

On Wed, Jul 13, 2011 at 11:22:26PM +0200, Jesper Juhl wrote:
> In drivers/mfd/tps65910.c:tps65910_i2c_probe() there's potential for a
> tiny optimization.
> 
> We assign to init_data->irq and init_data->irq_base long before we
> need them, and there are two potential exits from the function before
> they are needed.
> 
> Moving the assignments below these two potential exits means we
> completely avoid doing them in these two (failure) cases.
Patch applied, thanks.

Cheers,
Samuel.

-- 
Intel Open Source Technology Centre
http://oss.intel.com/

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2011-07-27  9:51 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-07-13 21:22 [PATCH] mfd: avoid two assignments if failures happen in tps65910_i2c_probe Jesper Juhl
2011-07-15  9:12 ` Graeme Gregory
2011-07-27  9:52 ` Samuel Ortiz

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