On Wed, Dec 19, 2001 at 09:30:19PM -0800, David S. Miller wrote:
> Don't the PCI specs actually talk about 24-bits in fact?
>
> Russell does you box really have the full 32-bits or is it
> really just 24-bits?
Shrug - the chip documentation isn't good enough to indicate either.
What I do know is:
- setting the bridge and eepro100 up with 16-bit IO addresses causes PCI
master aborts.
- setting the bridge and eepro100 up with 32-bit IO addresses which
correspond to the host MMIO region, it works perfectly.
It appears that the first bridge converts the mmio access into a PCI
IO read/write cycle without any address translation. So, when I
access mmio 0x90011000, it would appear to cause a PCI IO cycle at
the same address.
The MMIO region for this bus is 0x90010000 - 0x9001ffff, so its impossible
to test the effect of different upper 16-bits.
I suppose I could waste some time by getting Linux to generate lots of IO
cycles and scoping the PCI bus lines to find the PCI address, but I think
its rather academic in light of the above.
--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux
http://www.arm.linux.org.uk/personal/aboutme.html
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This archive was generated by hypermail 2b29 : Sun Dec 23 2001 - 21:00:21 EST