[PATCH 07/12] drivers/media: Employ atomic_fetch_inc()

[PATCH 07/12] drivers/media: Employ atomic_fetch_inc()

[Davidlohr Bueso]

Now that we have fetch_inc() we can stop using inc_return() - 1.

These are very similar to the existing OP-RETURN primitives we already
have, except they return the value of the atomic variable _before_
modification.

Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: linux-media@vger.kernel.org
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 drivers/media/pci/cobalt/cobalt-driver.c | 2 +-
 drivers/media/pci/cx18/cx18-driver.c     | 2 +-
 drivers/media/v4l2-core/v4l2-device.c    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c
index 8d6f04fc8013..70dfcb0c6a72 100644
--- a/drivers/media/pci/cobalt/cobalt-driver.c
+++ b/drivers/media/pci/cobalt/cobalt-driver.c
@@ -683,7 +683,7 @@ static int cobalt_probe(struct pci_dev *pci_dev,
 	int i;
 
 	/* FIXME - module parameter arrays constrain max instances */
-	i = atomic_inc_return(&cobalt_instance) - 1;
+	i = atomic_fetch_inc(&cobalt_instance);
 
 	cobalt = kzalloc(sizeof(struct cobalt), GFP_ATOMIC);
 	if (cobalt == NULL)
diff --git a/drivers/media/pci/cx18/cx18-driver.c b/drivers/media/pci/cx18/cx18-driver.c
index 260e462d91b4..5cb3408c6859 100644
--- a/drivers/media/pci/cx18/cx18-driver.c
+++ b/drivers/media/pci/cx18/cx18-driver.c
@@ -908,7 +908,7 @@ static int cx18_probe(struct pci_dev *pci_dev,
 	struct cx18 *cx;
 
 	/* FIXME - module parameter arrays constrain max instances */
-	i = atomic_inc_return(&cx18_instance) - 1;
+	i = atomic_fetch_inc(&cx18_instance);
 	if (i >= CX18_MAX_CARDS) {
 		printk(KERN_ERR "cx18: cannot manage card %d, driver has a "
 		       "limit of 0 - %d\n", i, CX18_MAX_CARDS - 1);
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 06fa5f1b2cff..1bc5b68c2724 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -76,7 +76,7 @@ EXPORT_SYMBOL_GPL(v4l2_device_put);
 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
 						atomic_t *instance)
 {
-	int num = atomic_inc_return(instance) - 1;
+	int num = atomic_fetch_inc(instance);
 	int len = strlen(basename);
 
 	if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
-- 
2.6.6

Re: [PATCH 07/12] drivers/media: Employ atomic_fetch_inc()

[Mauro Carvalho Chehab]

Em Mon, 20 Jun 2016 13:05:59 -0700
Davidlohr Bueso <dave@stgolabs.net> escreveu:

> Now that we have fetch_inc() we can stop using inc_return() - 1.
> 
> These are very similar to the existing OP-RETURN primitives we already
> have, except they return the value of the atomic variable _before_
> modification.
> 
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> Cc: Andy Walls <awalls@md.metrocast.net>
> Cc: linux-media@vger.kernel.org
> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>

I suspect that you'll be applying this together with the other patches
in this series. So:

Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

> ---
>  drivers/media/pci/cobalt/cobalt-driver.c | 2 +-
>  drivers/media/pci/cx18/cx18-driver.c     | 2 +-
>  drivers/media/v4l2-core/v4l2-device.c    | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c
> index 8d6f04fc8013..70dfcb0c6a72 100644
> --- a/drivers/media/pci/cobalt/cobalt-driver.c
> +++ b/drivers/media/pci/cobalt/cobalt-driver.c
> @@ -683,7 +683,7 @@ static int cobalt_probe(struct pci_dev *pci_dev,
>  	int i;
>  
>  	/* FIXME - module parameter arrays constrain max instances */
> -	i = atomic_inc_return(&cobalt_instance) - 1;
> +	i = atomic_fetch_inc(&cobalt_instance);
>  
>  	cobalt = kzalloc(sizeof(struct cobalt), GFP_ATOMIC);
>  	if (cobalt == NULL)
> diff --git a/drivers/media/pci/cx18/cx18-driver.c b/drivers/media/pci/cx18/cx18-driver.c
> index 260e462d91b4..5cb3408c6859 100644
> --- a/drivers/media/pci/cx18/cx18-driver.c
> +++ b/drivers/media/pci/cx18/cx18-driver.c
> @@ -908,7 +908,7 @@ static int cx18_probe(struct pci_dev *pci_dev,
>  	struct cx18 *cx;
>  
>  	/* FIXME - module parameter arrays constrain max instances */
> -	i = atomic_inc_return(&cx18_instance) - 1;
> +	i = atomic_fetch_inc(&cx18_instance);
>  	if (i >= CX18_MAX_CARDS) {
>  		printk(KERN_ERR "cx18: cannot manage card %d, driver has a "
>  		       "limit of 0 - %d\n", i, CX18_MAX_CARDS - 1);
> diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
> index 06fa5f1b2cff..1bc5b68c2724 100644
> --- a/drivers/media/v4l2-core/v4l2-device.c
> +++ b/drivers/media/v4l2-core/v4l2-device.c
> @@ -76,7 +76,7 @@ EXPORT_SYMBOL_GPL(v4l2_device_put);
>  int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
>  						atomic_t *instance)
>  {
> -	int num = atomic_inc_return(instance) - 1;
> +	int num = atomic_fetch_inc(instance);
>  	int len = strlen(basename);
>  
>  	if (basename[len - 1] >= '0' && basename[len - 1] <= '9')



Thanks,
Mauro