Frederic,
> > Have you tried check_mem_region and request_mem_region? They would
> > seem to be the appropriate incantations here.
> >
>
> I'm not sure but I think this 2 functions are only available
> in V2.3. In
> my case I use a
> V2.2.
All right, I am using V3preWhatever and am not aware as to what
functions are available in which releases. Still, my second argument holds,
if you *know* that no-one else is using the board, simply use the addresses
and do not make a big thing of the request_region problem.
> When I write to my memory LOOKUP, and read it immediately,
> the read and the write are identical but If I read it just after, it
> seems
> the whole memory is filled with the last value
I suspect that if you wrote one address, then wrote a second, then
read the first it would show the value written into the second. In other
words, I expect that every write is returning the last read value. Are you
certain that the memory on the board is read/write and not write only? I've
seen stranger things...
I just noticed that you are accessing this memory with dereferenced
pointers. You should really use the readb/readw/readl and
writeb/writew/writel functions to access PCI memory. You may get away with
your pointers on a PC, but I am not certain. Everything I have read
suggests using the read/write routines.
> ... explicit example deleted ...
Other questions in an attempt to help (I am really in over my head here):
1) Are you certain that your board is not functioning properly, even though
you can not read-back the data from the board?
2) Might check_region fail if the memory is write only?
3) You might try remapping the memory region (modify the base address
register in the PCI config registers). There does not seem to be any good
way to request a block of memory to use, but I've found that the vast
majority of the upper PCI memory is generally unused. I have been putting
things at 0xC0000000 (and above) lately.
Regards,
Steve
P.S. If you find a good way to request a block of PCI memory, please let me
know.
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