Re: [PATCH 10/13] BLK_DEV_IDE_CELLEB dependency fix

From: Al Viro
Date: Thu Mar 15 2007 - 04:47:14 EST


On Thu, Mar 15, 2007 at 03:10:20PM +0900, Akira Iguchi wrote:
> Al wrote:
> >
> >Eh... You still need dependency on IDE=y; otherwise you'll get configs
> >with IDE=m, BLK_DEV_IDE_CELLEB=y and those won't link. BLK_DEV_IDEDMA_PCI
> >is selectable just fine with IDE=m.
> >
> >It's the same problem as with ps3 fb.
> >
>
> I'm sorry I missed this case.
> Using some configurations, I found BLK_DEV_IDE=y was better.
> (I failed to link when IDE=y and BLK_DEV_IDE=m.)

Umm... Point taken. After looking at the entire thing... well.

a) BLK_DEV_IDE_PMAC has bogus dependency on IDE=y. If anything, that
should've been BLK_DEV_IDE=y; however, it *does* build with ide modular -
it doesn't generate a separate module and its initialization is called
explicitly from ide one. AFAICS, we can simply drop that dependency.

b) BLK_DEV_IDE_PMAC does *not* build without BLK_DEV_IDEDMA_PMAC. Quoting
benh, "I don't see any reason to keep that dma thingy optional anyway".

c) BLK_DEV_MPC8xx_IDE depends on BLK_DEV_IDE=y *and* IDE=y. The latter is
obviously redundant. The former... No idea, 8xx is currently b0rken in
ARCH=powerpc and I can't be arsed to wade through arch/ppc bitrot. As it
is, driver definitely wants ARCH=ppc stuff (__res, for one thing).

Now, BLK_DEV_IDE_CELLEB looks interesting. The nature of breakage is not
the same as usual (non-modular driver depends on stuff that might be built
modular); what's going on here is funnier. If you get ide-core modular,
you'll have BLK_DEV_IDE_CELLEB code *linked* *into* ide-core.ko. Unlike
the rest of its ilk, however, it doesn't have its init called directly from
ide init. It uses module_init(), which happens to work when it goes into
the kernel image (ide-core.o has several initcalls, not a problem), but breaks
when it goes into a modular ide-core.ko; there multiple module_init() are
fatal.

So AFAICS the minimal fix for that sucker is dependency on BLK_DEV_IDE=y;
however, I really wonder if
* it needs to be linked into ide-core (as opposed to being a normal
module of its own)
* alternatively, its init should be called explicitly.

Comments?
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