Re: [linux-fbdev] [PATCH 2.3.x] fbdev reversion

On Wed, Mar 15, 2000, Gabriel Paubert [off-list ref] wrote:

quoted

#define _IO_BASE       0

breaks CHRP and PReP boxes that use plain ISA drivers (inb() and friends).

Indeed, but that's unavoidable. Except that the breakage has to wait for
2.5 to be acceptable. Given the choice I prefer to break this and properly
use resources even for drivers which believe that they have to use fixed
addresses assigned by God, or rather the devil given the mess that the PC
`architecture' is.

Well, we need a fix _now_ (that I will backport to 2.2.x as soon as
possible too), at least for PowerMacs. The problem of ISA drivers with
legacy hard-coded addresses is indeed a real one, but it can be
temporarily worked around by having the kernel maintaing a separate
mapping of the "old" IO base to the legacy ISA bus if one exist.

We have, I think, no legacy code using /proc/bus/pci, do we ? If I'm
right, then we can chance it to return physical addresses without
breaking anyone so at least we have a temporary fix for XFree. We must
get the kernel<->userland interface right asap so that we don't need to
change XFree again and again.

I'll play a bit with Michel patches next week-end. Unfortunately, I can't
test much on 2.3.x until the OHCI driver is fixed.

Ben.


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