[PATCH] rfkill: print events when input handler is disabled/enabled

[PATCH] rfkill: print events when input handler is disabled/enabled

[Johannes Berg]

It is useful for debugging when we know if something disabled
the in-kernel rfkill input handler.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/rfkill/core.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- wireless-testing.orig/net/rfkill/core.c	2009-06-07 11:46:05.000000000 +0200
+++ wireless-testing/net/rfkill/core.c	2009-06-07 11:53:40.000000000 +0200
@@ -1134,7 +1134,8 @@ static int rfkill_fop_release(struct ino
 
 #ifdef CONFIG_RFKILL_INPUT
 	if (data->input_handler)
-		atomic_dec(&rfkill_input_disabled);
+		if (atomic_dec_return(&rfkill_input_disabled) == 0)
+			printk(KERN_DEBUG "rfkill: input handler enabled\n");
 #endif
 
 	kfree(data);
@@ -1157,7 +1158,8 @@ static long rfkill_fop_ioctl(struct file
 	mutex_lock(&data->mtx);
 
 	if (!data->input_handler) {
-		atomic_inc(&rfkill_input_disabled);
+		if (atomic_inc_return(&rfkill_input_disabled) == 1)
+			printk(KERN_DEBUG "rfkill: input handler disabled\n");
 		data->input_handler = true;
 	}
 

Re: [PATCH] rfkill: print events when input handler is disabled/enabled

[Marcel Holtmann]

Hi Johannes,

> It is useful for debugging when we know if something disabled
> the in-kernel rfkill input handler.
> 
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
> ---
>  net/rfkill/core.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> --- wireless-testing.orig/net/rfkill/core.c	2009-06-07 11:46:05.000000000 +0200
> +++ wireless-testing/net/rfkill/core.c	2009-06-07 11:53:40.000000000 +0200
> @@ -1134,7 +1134,8 @@ static int rfkill_fop_release(struct ino
>  
>  #ifdef CONFIG_RFKILL_INPUT
>  	if (data->input_handler)
> -		atomic_dec(&rfkill_input_disabled);
> +		if (atomic_dec_return(&rfkill_input_disabled) == 0)
> +			printk(KERN_DEBUG "rfkill: input handler enabled\n");
>  #endif
>  
>  	kfree(data);
> @@ -1157,7 +1158,8 @@ static long rfkill_fop_ioctl(struct file
>  	mutex_lock(&data->mtx);
>  
>  	if (!data->input_handler) {
> -		atomic_inc(&rfkill_input_disabled);
> +		if (atomic_inc_return(&rfkill_input_disabled) == 1)
> +			printk(KERN_DEBUG "rfkill: input handler disabled\n");
>  		data->input_handler = true;
>  	}

do you really think the == 1 is the correct thing here. I think that
should be a > 0.

Regards

Marcel

Re: [PATCH] rfkill: print events when input handler is disabled/enabled

[Johannes Berg]

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On Sun, 2009-06-07 at 17:25 +0200, Marcel Holtmann wrote:

> >  	if (!data->input_handler) {
> > -		atomic_inc(&rfkill_input_disabled);
> > +		if (atomic_inc_return(&rfkill_input_disabled) == 1)
> > +			printk(KERN_DEBUG "rfkill: input handler disabled\n");
> >  		data->input_handler = true;
> >  	}
> 
> do you really think the == 1 is the correct thing here. I think that
> should be a > 0.

Why would you want to know every time somebody uses the ioctl? I think
the first time should be sufficient, no? Common case will hopefully be
only one program using it anyway though.

johannes

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Re: [PATCH] rfkill: print events when input handler is disabled/enabled

[Marcel Holtmann]

Hi Johannes,

> > >  	if (!data->input_handler) {
> > > -		atomic_inc(&rfkill_input_disabled);
> > > +		if (atomic_inc_return(&rfkill_input_disabled) == 1)
> > > +			printk(KERN_DEBUG "rfkill: input handler disabled\n");
> > >  		data->input_handler = true;
> > >  	}
> > 
> > do you really think the == 1 is the correct thing here. I think that
> > should be a > 0.
> 
> Why would you want to know every time somebody uses the ioctl? I think
> the first time should be sufficient, no? Common case will hopefully be
> only one program using it anyway though.

you are right, we only care about the printk once. No need to keep
printing it on every change.

Acked-by: Marcel Holtmann <marcel@holtmann.org>

Regard

Marcel