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SubjectWeird PCI problem

Hi there,

I have a customer with a pretty weird problem.

- Pentium MMX 200MHz
- AMI BIOS
- Intel Triton II chipset
- Cyclades Cyclom-YeP (32 ports)
- Linux Red Hat
- Kernel 2.0.36 (stock kernel, not RPM)

When the driver is built into the kernel (monolythic), the Cyclades card
is detected by the kernel, but no interrupts are generated by the card.

Analyzing the problem a little further, I noticed that /proc/pci yells:

$ cat /proc/pci
PCI devices found:
<snip>
Communication controller: Cyclades Cyclom-Y above 1Mbyte (rev 1).
Medium devsel. Fast back-to-back capable. IRQ 15. Master Capable.
Latency=32.
Non-prefetchable 32 bit memory at 0xe031a000.
I/O at 0x6200.
I/O at 0xe0310000.
^^^^^^^^^^^^^^^^^
, when it should be yelling:

$ cat /proc/pci
PCI devices found:
<snip>
Bus 0, device 18, function 0:
Communication controller: Cyclades Cyclom-Y above 1Mbyte (rev 1).
Medium devsel. Fast back-to-back capable. IRQ 15. Master Capable.
Latency=32.
Non-prefetchable 32 bit memory at 0xe031a000.
I/O at 0x6200.
Non-prefetchable 32 bit memory at 0xe0310000.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
For those who know PCI: the first address bits (before the masking) are
0x01, which means the address is being allocated as an I/O address.
However, I am _sure_ the card _requests_ a 32-bit memory address (bits
equals 0x00), yet it's being assigned an I/O adress instead.

Another interesting info: I was thinking it to be a PCI BIOS problem, but
then, by booting the system from a DOS floppy and running a diagnostics
utility, I was able to see that, under DOS, the first address bits for
that address were correctly set to 0x00. Dunno whether this releases the
BIOS from being the culprit, but it's kinda weird ...

Furthermore, under this DOS environment in the same system the card
performs flawlessly.

As additional info:

- I tested the HW itself and it's ok.
- I swapped the card by another one that I tested in a different system,
and it had the same problem;

Any hints ???

TIA for your help.

Regards,
Ivan


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