Re: Big Fix for 2.2.1

Linus Torvalds (torvalds@transmeta.com)
Wed, 27 Jan 1999 12:05:36 -0800 (PST)

On Wed, 27 Jan 1999, Linux Lists wrote:
>
> Please don't do that. The Cyclades driver supports both ISA and PCI cards,
> and it follows correctly the current definition, by ioremap'ing addresses
> above 1MB and using readX/writeX for _all_ accesses to MMIO resources (in
> ISA or PCI). Doing this change would mean having to test which card I'm
> accessing _every time_ I do a readX/writeX, which is completelly
> unacceptable (for obvious performance reasons).

Note that for drivers that already are PCI-aware, the trivial fix is to
just make them _always_ ioremap() their area (whether it is in the ISA
legacy region or not) and then use readX/writeX. That works now, and will
always work - that's how ioremap() is supposed to handle it.

It's only for drivers that _only_ know about legacy ISA issues that this
would be an issue.

Linus

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