Re: Troubles with NCR controller (was: Unidentified subject!)

Gerard Roudier (
Wed, 13 Nov 1996 00:14:39 +0000 (GMT)

IOMAPPED means: controller io registers mapped into io space.
MEMORYMAPPED means: controller io registers mapped into memory space.

MMIO means: memory mapped io (=MEMORYMAPPED)

I agree that confusion is indeed possible.

Linux-2.0.X does not support MMIO though PCI bus on Alpha. So option
IOMAPPED should be set to Y for NCR53C8XX driver.
Otherwise, the system will crash at start-up.

In driver revision 1.12c, the driver just ignore this option and forced
IOMAPPED on Alpha. I have removed the corresponding stuf (#ifdef
__alpha__) for Linux-2.1.something_that_supports_pci_mmio_on_alpha.

I will add a condition involving LINUX_VERSION_CODE for 2.0.X in the next
revision of the driver.

Sorry if you had problems under Alpha with the driver 1.14/a/c.


On Mon, 11 Nov 1996, Michal Jaegermann wrote:

> Gerard wrote:
> > >
> > >As you know, under linux-2.0.X/Alpha, memory mapped io does not work.
> > >So, if you update the driver to 1.14 in a 2.0.X kernel, you _must_
> > >force NORMAL IO,
> Well, yes, I though so from some earlier postings.
> I always thought that "_IOMAPPED=y" will set memory mapped io, which
> on axp does not work. Am I misreading something? To add to this
> confusion all NCR controllers (a few) for which I left
> seem to be working just fine (and quite heavily on occasions).
> Michal

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