Re: [RFC v1 01/16] lib: devres: don't enclose pcim_*() functionsin CONFIG_HAS_IOPORT

[Russell King - ARM Linux]

On Tue, Dec 11, 2012 at 05:16:10PM +0000, Alan Cox wrote:
> > Correct.  If HAS_IOPORT is not selected then we are potentially missing
> > the dependent functions (because the platform has no IOPORT support) _or_
> > it does have ISA/PCI IO spaces _but_ they're not mappable via the
> > ioport_map() mechanism due to some non-linearity involved in the
> > translation.
> > 
> > To make that second point clear, that's platforms where:
> > 
> > 	ioport_map(addr + 4) != ioport_map(addr) + 4.
> 
> For inb/inw and friends this shouldn't matter.

Exactly, and you wouldn't be using inb/inw with ioport_map().

The problem comes when you end up trying to deal with stuff which
uses ioread{8,16} on ioport_map() cookies where it's assumed that
adding N to the cookie is the same as adding N to the port address.

Thankfully those platforms aren't going to be a part of the single
zImage project...
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/