init functions

[Paul M. <pm...@mv...>]

Hello,

As I'm sure people have already begun noticing.. for frame buffer drivers,
we typically have something like:

int __init myfb_init(void)
{
	...
}

static void __exit myfb_exit(void)
{
	...
}

#ifdef MODULE
module_init(myfb_init);
#endif
module_exit(myfb_exit);

This is absolutely and completely broken beyond belief. module_init() takes
care of inserting the init function into the .initcall.init section which
does the initialization at boot time or when the module is inserted.

In addition to this, we're making a function that should be private global,
and we're using a cheap hack to use another cheap hack. Which brings me to
my next point.. for this bit, I direct you to fbmem_init().. particularly:

	for (i =3D 0; i < NUM_FB_DRIVERS; i++)
		if (fb_drivers[i].init)
			fb_drivers[i].init();

Now this is cute and all, but it's about as practical as using a bulldozer
to hunt down small furry creatures.

I can see how the above method might've been necessary in 2.1 and most of
2.2, but it's certainly not needed anymore. The only time it would've been
practical is when drivers were using the whole init_module()/cleanup_module=
()
thing.. where init_module() was simply a wrapper that ran the init routine
from inside the driver.

If there are any drivers left that are still using this, they're broken and
out of date anyways, and should be fixed. Even 2.2 has supported the
module_init()/module_exit() calls for quite awhile now..

For now, I suggest something like:

--- linux.orig/drivers/video/fbmem.c    Fri Jun 29 12:47:03 2001
+++ linux/drivers/video/fbmem.c Fri Jun 29 13:12:08 2001
@@ -826,10 +826,6 @@
         */
        for (i =3D 0; i < num_pref_init_funcs; i++)
                pref_init_funcs[i]();
-
-       for (i =3D 0; i < NUM_FB_DRIVERS; i++)
-               if (fb_drivers[i].init)
-                       fb_drivers[i].init();
 }

to get around stepping into the init function twice, so we can finally
get rid of the #ifdef MODULE around the module_init(), and finally make
the init call static.

Ideally, I'd like to do away with the fb_drivers[] entirely and simply move
to a linked list where drivers insert themselves when they register with
register_framebuffer(). I plan to work on a patch for this on the weekend.

Comments?

Regards,

--=20
Paul Mundt <pm...@mv...>
MontaVista Software, Inc.