Re: [PATCH 3/4] Fix remaining big endian issue of hfcmulti

[Karsten Keil]

On Tue, Aug 05, 2008 at 11:42:56AM -0700, Linus Torvalds wrote:
> 
> 
> On Tue, 5 Aug 2008, Karsten Keil wrote:
> > 
> > Maybe we can use the trick from lib/iomap.c to detect which
> > kind of IO is needed, but unfortunately PIO_OFFSET, PIO_MASK and
> > PIO_RESERVED are not exported so it would need to copy the defines, which
> > isn't a really clean solution.
> 
> Even if they were exported, you couldn't.
> 
> lib/iomap.c is _not_ generic code. It's a library function for 
> architectures that don't do it some other way. But various architectures 
> can choose to not use lib/iomap.c at all - for example, they may have MMIO 
> and PIO in the same address space, so they don't need the conditionals at 
> all (because all the work was done at mapping time, not at runtime).
> 
> So if you actually have different models of operation for PIO and MMIO, 
> then yes, you need to handle that in the driver itself.
> 

One question here, what is the better approach to do such a different
implementation, use one local function like

static void
my_out32(struct card *c, u_int offset, u-int data) 
{
	if (c->mode == MMIO) {
		...
	} else {
		...
	}
}

or use 2 function, one for the MMIO and one for the PIO model and then use
indirect calls (like c->my_out32(...)) ?

-- 
Karsten Keil
SuSE Labs
ISDN and VOIP development
SUSE LINUX Products GmbH, Maxfeldstr.5 90409 Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg)
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