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RE: Multifunction devices



If I recall correctly, 'ghost' config spaces on multifunction devices
violates the PCI spec and PC'99 requirements.  This problem is should not be
expected in any new silicon.
-- BrooksL

> -----Original Message-----
> From: dahlin@wa.freei.net [mailto:dahlin@wa.freei.net]
> Sent: Thursday, 25 May, 2000 02:22
> To: pci-sig@znyx.com
> Subject: Multifunction devices
> 
> 
> We have a custom IC that just had first silicon show up in 
> our lab.  It is a
> multifunction device with two functions.  So far we have 
> found one problem in
> the PCI interface
> 
> That problem is that the device issues a DEVSEL# for config 
> space accesses to
> all 8 possible functions.  The result is that we have 2 
> functioning config spaces
> and 6 config spaces that have read-only registers that contain 0's.  
> 
> This is not a good thing, but I think it is a problem that 
> can be lived with.
>  The BARs return all 0's when read so the system won't 
> allocate any space to
> the 6 extra devices, and we won't conflict with any other 
> config spaces.
> 
> Does anyone see a problem with not spending the time and 
> money on fixing this
> if it remains that only bug?
> 
> Thanks,
> Dahlin
>