[PATCH 17/31] staging: comedi: ni_daq_700: remove unused private data variable

[PATCH 17/31] staging: comedi: ni_daq_700: remove unused private data variable

[H Hartley Sweeten]

The 'have_irq' variable is not needed since this driver doesn't
use interrupts. Remove it.

The kfree(s->private) needs to remain to free the memory allocated
in subdev_700_init().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: Greg Kroah-hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/comedi/drivers/ni_daq_700.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_daq_700.c b/drivers/staging/comedi/drivers/ni_daq_700.c
index 2f84934..525f076 100644
--- a/drivers/staging/comedi/drivers/ni_daq_700.c
+++ b/drivers/staging/comedi/drivers/ni_daq_700.c
@@ -69,7 +69,6 @@ struct dio700_board {
 struct subdev_700_struct {
 	unsigned long cb_arg;
 	int (*cb_func) (int, int, int, unsigned long);
-	int have_irq;
 };
 
 #define CALLBACK_ARG	(((struct subdev_700_struct *)s->private)->cb_arg)
@@ -166,9 +165,7 @@ static void subdev_700_cleanup(struct comedi_device *dev,
 			       struct comedi_subdevice *s)
 {
 	if (s->private)
-		if (subdevpriv->have_irq)
-
-			kfree(s->private);
+		kfree(s->private);
 }
 
 static int dio700_attach(struct comedi_device *dev, struct comedi_devconfig *it)
-- 
1.7.11

Re: [PATCH 17/31] staging: comedi: ni_daq_700: remove unused private data variable

[Dan Carpenter]

On Fri, Jun 22, 2012 at 04:26:46PM -0700, H Hartley Sweeten wrote:
> The 'have_irq' variable is not needed since this driver doesn't
> use interrupts. Remove it.
> 
> The kfree(s->private) needs to remain to free the memory allocated
> in subdev_700_init().
> 

Hm...  That's weird.  The function which set have_irq to 1 was never
called and you already removed it in a previous patch.

So this fixes a memory leak right?  Because the kfree() was never
called in the original code.  Please mark bug fixes as special if
you can.

>  #define CALLBACK_ARG	(((struct subdev_700_struct *)s->private)->cb_arg)
> @@ -166,9 +165,7 @@ static void subdev_700_cleanup(struct comedi_device *dev,
>  			       struct comedi_subdevice *s)
>  {
>  	if (s->private)
> -		if (subdevpriv->have_irq)
> -
> -			kfree(s->private);
> +		kfree(s->private);

You could also remove the: "if (s->private)" check.

regards,
dan carpenter