Messages in this thread | | | Date | Tue, 11 Dec 2012 17:34:50 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [RFC v1 01/16] lib: devres: don't enclose pcim_*() functions in CONFIG_HAS_IOPORT |
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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...
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