Subject: Re: [patch 3/4] macintosh: replace deprecated __initcall with device_initcall

From: Michael Ellerman <[email-masked]>
Date: Thu, 15 May 2008 19:08:37 +1000

On Wed, 2008-05-14 at 23:41 -0700, Andrew Morton wrote:
> On Thu, 15 May 2008 16:28:28 +1000 Michael Ellerman <[email-masked]> wrote:
> 
> > On Wed, 2008-05-14 at 23:06 -0700, Andrew Morton wrote:
> > > On Thu, 15 May 2008 14:14:38 +1000 Paul Mackerras <[email-masked]> wrote:
> > > 
> > > > [email-masked] writes:
> > > > 
> > > > > -__initcall(adb_init);
> > > > > +device_initcall(adb_init);
> > > > 
> > > > There's no particular reason why this needs to go in 2.6.26, is there?
> > > > It looks to me like something that I should queue up for 2.6.27.
> > > > 
> > > 
> > > No, this make no difference in code generation - it's just a
> > > use-the-modern-interface thing.
> > 
> > I missed the memo about __initcall being deprecated, or is it only
> > deprecated for use in device drivers?
> > 
> 
> It's just old-fashioned, that's all.
>
> #define pure_initcall(fn)		__define_initcall("0",fn,0)
> 
> #define core_initcall(fn)		__define_initcall("1",fn,1)
> #define core_initcall_sync(fn)		__define_initcall("1s",fn,1s)
> #define postcore_initcall(fn)		__define_initcall("2",fn,2)
> #define postcore_initcall_sync(fn)	__define_initcall("2s",fn,2s)
> #define arch_initcall(fn)		__define_initcall("3",fn,3)
> #define arch_initcall_sync(fn)		__define_initcall("3s",fn,3s)
> #define subsys_initcall(fn)		__define_initcall("4",fn,4)
> #define subsys_initcall_sync(fn)	__define_initcall("4s",fn,4s)
> #define fs_initcall(fn)			__define_initcall("5",fn,5)
> #define fs_initcall_sync(fn)		__define_initcall("5s",fn,5s)
> #define rootfs_initcall(fn)		__define_initcall("rootfs",fn,rootfs)
> #define device_initcall(fn)		__define_initcall("6",fn,6)
> #define device_initcall_sync(fn)	__define_initcall("6s",fn,6s)
> #define late_initcall(fn)		__define_initcall("7",fn,7)
> #define late_initcall_sync(fn)		__define_initcall("7s",fn,7s)
> 
> #define __initcall(fn) device_initcall(fn)
> 
> See, we have the nicely-ordered foo_initcall()'s, and the old-fashioned
> legacy __initcall happens to map onto device_initcall().
> 
> Such code should use device_initcall() directly.  So we see at which
> stage in initcalls this function will be called.

Yeah fair enough. 

A little git'ing tells me there were 31 new __initcall()'s added between
2.6.24 and 2.6.25, and there are 12 more lurking between 2.6.25 and
linux-next. They're breeding!

You can't stick a #warning inside a #define can you? How about:

#define __initcall(fn)				\
do {						\
int Use_device_initcall_not___initcall_please;	\
device_initcall(fn);				\
} while (0)

Which gives:
warning: unused variable ‘Use_device_initcall_not___initcall_please’

..

Yeah OK that was a joke.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person