Re: [RFC] Relaxed PIO read vs. DMA write ordering

[Jesse Barnes]

On Wed, Jan 07, 2004 at 03:27:54PM -0800, Greg KH wrote:
> On Wed, Jan 07, 2004 at 03:07:12PM -0800, Jesse Barnes wrote:
> > 
> >   1) add pcix_enable_relaxed() and read_relaxed() (read() would always be
> >      ordered)
> 
> This probably preserves the current situation best, enabling driver
> writers to be explicit in knowing what is happening.

That's what I figured too.  It also seems like it has the lowest
probability of introducing PIO vs. DMA races, since you have to
explicitly change a read() call.

What about compatibility though?  How should the interface behave if
it's accessing a PCI-X device that happens to be in PCI mode?  Ideally,
we could add these calls in and introduce no penalty for platforms that
don't support it...

Thanks,
Jesse
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