Point of detail: don't forget to run 'make clean' after applying this
series. Modules are not automatically rebuilt after changes to our
io_mm.h (should they?)
Cheers,
Michael
Am 02.06.2021 um 17:21 schrieb Michael Schmitz:
Finn Thain found out that our multiplatform support is broken when
attempting to build a kernel with support for both Q40 and Atari (when
setting CONFIG_ISA through CONFIG_Q40, but not CONFIG_ATARI_ROM_ISA).
Inspection of the code in io_mm.h reveals that in that case, ISA I/O
accessors with address translation are used for the Atari IDE driver, where
MMIO accessors with no address translation would have been appropriate.
Setting CONFIG_ATARI_ROM_ISA will fix the issue for Atari, but then force the
use of I/O accessors without address translation for Q40. The code in
io_mm.h is fundamentally broken for kernels that have both Q40 and Atari
support.
Address this by adding a check for address < 1024 to the Atari address
translation case, changing the default address translation to return the
untranslated address, and changing the CONFIG_ATARI_ROM_ISA section to use
ISA I/O accessors for addresses > 1024 (i.e., those not intended to map to
the ROM port).
Tested on ARAnyM with all combinations of CONFIG_ATARI_ROM_ISA and
CONFIG_ISA. Earlier versions tested on my Falcon hardware, all using
pata_falcon.
A thorough review in particular in regard to ramifications for Q40 and Amiga
would be welcome. If there is a better way to implement these changes, I'd
appreciate a hint. This is all academic as long as support for Q40 and Atari
in the same kernel image is not needed, of course.
I suspect patch 2 may not be needed, since the isa_sex variable should always
be zero?
Cheers,
Michael
