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SubjectRe: [PATCH] Clarify pci_iomap() usage for MMIO-only devices
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On Tue, 2007-09-18 at 12:03 -0700, Linus Torvalds wrote:
>
> On Tue, 18 Sep 2007, Luis R. Rodriguez wrote:
> >
> > Alright, here is the same patch inline with s/recommended/required/ language:
>
> Well, the thing is, I'm not at all sure that I agree with this.
>
> If you use ioport_map/unmap, then you really *should* access them with the
> proper iomem accessors (ioread/iowrite). The fact that it may happen to
> work (when using the default lib/iomap.c implementation, at least) on
> some architectures and with the current implementation still doesn't mean
> that you should necessarily use readb/writeb.
>
> After all, you cannot use "inb/outb" on it, even if would happen to be an
> IO address.
>
> So what is this usage that wants to use the bogus accessor? Why not fix
> that instead of adding documentation for something that is very arguably
> something we want to *avoid* having people do!

Agreed.

ioremap -> readb/writeb
ioport_map/pci_iomap -> ioread/iowrite

and nothing else should be allowed.

Cheers,
Ben.


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