What is all the ram used for?

[Doug Ledford]

Mads Bondo Dydensborg wrote:
> 
> Hi there.
> 
> I have a
> 
>     SCSI storage controller: Adaptec AIC-7871 (rev 0).
>       Medium devsel.  Fast back-to-back capable.  IRQ 11.  Master
> Capable.  Latency=32.  Min Gnt=8.Max Lat=8.
>       I/O at 0xb000 [0xb001].
>       Non-prefetchable 32 bit memory at 0xcd000000 [0xcd000000].
> 
> Upon inspecting the non-prefetchable memory, it seems that there are 16 MB
> of it. (Writing 0xFFFFFFFF to it, reading back, 24 lower bits are blank).
> However, the aic7xxx driver never seems to ioremap more then 256 bytes of
> it.
> 
> Why is that? Is this memory somehow utilized elsewhere, or?
> 
> Any clarification would be greatly appreciated.

Your testing methodology is in error.  There isn't any more than 256 bytes
worth of registers on the card, and anything you might be seeing with your
test is the result of something else entirely.  The card doesn't even allow
32bit writes to portions of its register space, so you are certain to be
confusing the card when you run this test and that is likely to produce odd
results as well.

-- 

 Doug Ledford <dledford at redhat.com>  http://people.redhat.com/dledford
      Please check my web site for aic7xxx updates/answers before
                      e-mailing me about problems


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