From mboxrd@z Thu Jan 1 00:00:00 1970 In-Reply-To: Date: Wed, 15 Mar 2000 12:31:50 +0100 To: Gabriel Paubert , linux-fbdev@vuser.vu.union.edu, linuxppc-dev@lists.linuxppc.org From: Benjamin Herrenschmidt Subject: Re: [linux-fbdev] [PATCH 2.3.x] fbdev reversion Message-Id: <20000315123150.025617@mailhost.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Wed, Mar 15, 2000, Gabriel Paubert wrote: >> #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. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/