Re: [PATCH v2 5/9] drivers: net: Put prototype declaration for function sbni_probe() in sbni.c

[David Miller <davem@davemloft.net>]

From: Josh Triplett <josh@joshtriplett.org>
Date: Sat, 14 Dec 2013 19:41:49 -0800

> On Sat, Dec 14, 2013 at 10:26:58PM -0500, David Miller wrote:
>> From: Rashika Kheria <rashika.kheria@gmail.com>
>> Date: Sat, 14 Dec 2013 17:55:42 +0530
>> 
>> > This patch declares the prototype for the function sbni_probe() in file sbni.c.
>> > 
>> > Thus, it also removes the following warning in wan/sbni.c:
>> > drivers/net/wan/sbni.c:224:12: warning: no previous prototype for ‘sbni_probe’ [-Wmissing-prototypes]
>> > 
>> > Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
>> > ---
>> > 
>> > This revision fixes the following issues of the previous revision:
>> > Incorrect fix
>> > 
>> >  drivers/net/wan/sbni.c |    1 +
>> >  1 file changed, 1 insertion(+)
>> > 
>> > diff --git a/drivers/net/wan/sbni.c b/drivers/net/wan/sbni.c
>> > index 388ddf6..5061ffd 100644
>> > --- a/drivers/net/wan/sbni.c
>> > +++ b/drivers/net/wan/sbni.c
>> > @@ -221,6 +221,7 @@ static void __init sbni_devsetup(struct net_device *dev)
>> >  	dev->netdev_ops = &sbni_netdev_ops;
>> >  }
>> >  
>> > +int __init sbni_probe(int unit);
>> >  int __init sbni_probe(int unit)
>> 
>> This is not the correct way to fix this kind of warning, an exported
>> function needs to appear in a header file so that both the definition
>> and any callers of this function will see the same declaration in that
>> header file.
> 
> It should, yes; however, in this case, the function is one of several
> dozen that are directly prototyped and used by drivers/net/Space.c, and
> there's no header file prototyping any of those functions.
> 
> Do you have a suggestion for what header file should contain a prototype
> for this probe function?

Then create a Space.h for this.

Otherwise if something accidently makes the function signatures not match
at the call site vs. the definition, or vice versa, nothing will catch it.