[PATCH] spi: Clean up probe and remove functions

[PATCH] spi: Clean up probe and remove functions

[Jean Delvare]

While backporting 33cf00e5 ("spi: attach/detach SPI device to the ACPI
power domain"), I noticed that the code changes were suboptimal:

* Why use &spi->dev when we have dev at hand?

* After fixing the above, spi is used only once, so we don't really
  need a local variable for it.

This results in the following clean-up.

Signed-off-by: Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
Cc: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
Untested, no hardware.

 drivers/spi/spi.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

--- linux-3.14-rc2.orig/drivers/spi/spi.c	2014-02-13 14:42:09.309512009 +0100
+++ linux-3.14-rc2/drivers/spi/spi.c	2014-02-13 14:53:36.204366691 +0100
@@ -255,13 +255,12 @@ EXPORT_SYMBOL_GPL(spi_bus_type);
 static int spi_drv_probe(struct device *dev)
 {
 	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
-	struct spi_device		*spi = to_spi_device(dev);
 	int ret;
 
-	acpi_dev_pm_attach(&spi->dev, true);
-	ret = sdrv->probe(spi);
+	acpi_dev_pm_attach(dev, true);
+	ret = sdrv->probe(to_spi_device(dev));
 	if (ret)
-		acpi_dev_pm_detach(&spi->dev, true);
+		acpi_dev_pm_detach(dev, true);
 
 	return ret;
 }
@@ -269,11 +268,10 @@ static int spi_drv_probe(struct device *
 static int spi_drv_remove(struct device *dev)
 {
 	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
-	struct spi_device		*spi = to_spi_device(dev);
 	int ret;
 
-	ret = sdrv->remove(spi);
-	acpi_dev_pm_detach(&spi->dev, true);
+	ret = sdrv->remove(to_spi_device(dev));
+	acpi_dev_pm_detach(dev, true);
 
 	return ret;
 }


-- 
Jean Delvare
Suse L3 Support
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Re: [PATCH] spi: Clean up probe and remove functions

[Rafael J. Wysocki]

On 2/13/2014 3:28 PM, Jean Delvare wrote:
> While backporting 33cf00e5 ("spi: attach/detach SPI device to the ACPI
> power domain"), I noticed that the code changes were suboptimal:
>
> * Why use &spi->dev when we have dev at hand?
>
> * After fixing the above, spi is used only once, so we don't really
>    need a local variable for it.
>
> This results in the following clean-up.
>
> Signed-off-by: Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
> Cc: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Cc: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>


> ---
> Untested, no hardware.
>
>   drivers/spi/spi.c |   12 +++++-------
>   1 file changed, 5 insertions(+), 7 deletions(-)
>
> --- linux-3.14-rc2.orig/drivers/spi/spi.c	2014-02-13 14:42:09.309512009 +0100
> +++ linux-3.14-rc2/drivers/spi/spi.c	2014-02-13 14:53:36.204366691 +0100
> @@ -255,13 +255,12 @@ EXPORT_SYMBOL_GPL(spi_bus_type);
>   static int spi_drv_probe(struct device *dev)
>   {
>   	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
> -	struct spi_device		*spi = to_spi_device(dev);
>   	int ret;
>   
> -	acpi_dev_pm_attach(&spi->dev, true);
> -	ret = sdrv->probe(spi);
> +	acpi_dev_pm_attach(dev, true);
> +	ret = sdrv->probe(to_spi_device(dev));
>   	if (ret)
> -		acpi_dev_pm_detach(&spi->dev, true);
> +		acpi_dev_pm_detach(dev, true);
>   
>   	return ret;
>   }
> @@ -269,11 +268,10 @@ static int spi_drv_probe(struct device *
>   static int spi_drv_remove(struct device *dev)
>   {
>   	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
> -	struct spi_device		*spi = to_spi_device(dev);
>   	int ret;
>   
> -	ret = sdrv->remove(spi);
> -	acpi_dev_pm_detach(&spi->dev, true);
> +	ret = sdrv->remove(to_spi_device(dev));
> +	acpi_dev_pm_detach(dev, true);
>   
>   	return ret;
>   }
>
>

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Re: [PATCH] spi: Clean up probe and remove functions

[Mark Brown]

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On Thu, Feb 13, 2014 at 03:28:41PM +0100, Jean Delvare wrote:
> While backporting 33cf00e5 ("spi: attach/detach SPI device to the ACPI
> power domain"), I noticed that the code changes were suboptimal:
> 
> * Why use &spi->dev when we have dev at hand?
> 
> * After fixing the above, spi is used only once, so we don't really
>   need a local variable for it.

I've applied this but I have to say it's a bit marginal as a cleanup -
for example while we do only use the SPI device once it's not entirely
idiomatic to use to_spi_device() in the middle of the code rather than
at the top of the function so it's a small speed bump to see that.

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Re: [PATCH] spi: Clean up probe and remove functions

[Jean Delvare]

Hi Mark,

Le Friday 14 February 2014 à 15:03 +0000, Mark Brown a écrit :
> On Thu, Feb 13, 2014 at 03:28:41PM +0100, Jean Delvare wrote:
> > While backporting 33cf00e5 ("spi: attach/detach SPI device to the ACPI
> > power domain"), I noticed that the code changes were suboptimal:
> > 
> > * Why use &spi->dev when we have dev at hand?
> > 
> > * After fixing the above, spi is used only once, so we don't really
> >   need a local variable for it.
> 
> I've applied this but I have to say it's a bit marginal as a cleanup -
> for example while we do only use the SPI device once it's not entirely
> idiomatic to use to_spi_device() in the middle of the code rather than
> at the top of the function so it's a small speed bump to see that.

I don't disagree. The rationale for the change is that I simply reverted
to how the code was before 33cf00e5, assuming that the introduction of
spi as a local variable was caused by it being used more than once. If
you believe this was a good change on its own and would prefer to keep
it that way, I could send a patch replacing this one and only changing
&spi->dev to dev. Let me know.

And yes, this is not the most groundbreaking patch either way,
granted ;-)

-- 
Jean Delvare
Suse L3 Support

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Re: [PATCH] spi: Clean up probe and remove functions

[Mark Brown]

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On Fri, Feb 14, 2014 at 07:22:09PM +0100, Jean Delvare wrote:

> I don't disagree. The rationale for the change is that I simply reverted
> to how the code was before 33cf00e5, assuming that the introduction of
> spi as a local variable was caused by it being used more than once. If
> you believe this was a good change on its own and would prefer to keep
> it that way, I could send a patch replacing this one and only changing
> &spi->dev to dev. Let me know.

I do have a small preference for it but I don't care enough to suggest
you actually send that patch - if it annoyed me enough I'd just fix it
myself.

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