Messages in this thread | | | Date | Wed, 7 Jan 2004 15:56:33 -0800 | Subject | Re: [RFC] Relaxed PIO read vs. DMA write ordering | From | (Jesse Barnes) |
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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...
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