pSeries_request_regions()

[Benjamin Herrenschmidt]

On Tue, 2005-02-22 at 17:14 +1100, Anton Blanchard wrote:
> Hi John,
> 
> > During init, pSeries_request_regions() blindly requests ioports:
> > 00000000-0000001f : dma1
> > 00000020-0000003f : pic1
> > 00000040-0000005f : timer
> > 00000060-0000006f : reserved (no i8042)
> > 00000080-0000008f : dma page reg
> > 000000a0-000000bf : pic2
> > 000000c0-000000df : dma2
> > 
> > If I understand correctly, this is necessary for legacy ISA support.  A
> > system with purely virtual I/O would not need these reservations.  If I
> > should skip their reservation conditionally, should I check for the
> > mere existence of physical I/O?  Or for the existence of an ISA node?
> > Thoughts?
> 
> Yeah requesting those regions all the time is bogus. We can skip it if
> we dont have ISA, perhaps something like this:

Well...

The reason we request them in the first place is to prevent drivers from
mucking around with those bits of hardware no ? (so they fail their own
request_region).

I recently added a platform hook to deal with that in a slightly more
suitable way, though not all legacy drivers have been fixed yet to use
it.

Ben.