Subject: Re: Fwd: Located problem in pcn driver...
To: John Gordon <>
From: Jaromir Dolecek <>
List: tech-kern
Date: 04/18/2003 10:34:57
The address used for DMA is physical memory address. Do you say
that PCI and CPU see different physical memory adresses? That's
quite weird. Isn't it just bug in htole32() in handling of the
MSB or somewhere in the DMA code?

> > So, how do I fix this? Is the problem in this piece of code, or should the
> > ds_addr value already have been translated to a PCI-view address? Obviously,
> > for my testing it is simple to just set the top bit on the address, but how
> > do
> > I do this correctly, and where (in the driver here, or in the DMA code that
> > sets up the ds_addr value in the first place)?

If really PCI devices have different view of physical memory address
than CPU, then the correct place is the PCI-specific DMA code which sets up
the ds_addr value, methinks.

Jaromir Dolecek <>  
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