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SubjectRe: [PATCH] pci: print out DMA mask info
On Fri, Oct 10, 2008 at 10:18:33AM -0700, Roland Dreier wrote:
> > Open-coding DMA_BIT_MASK() within your driver means that we no longer
> > have a canonical list of DMA masks in one place. Instead we have to
> > grep the entire tree and come up with more-or-less complex scripts to
> > figure out which bit masks are actually in use.
>
> Out of curiousity, why do we care about that list?

Originally, I used to track down IO perf issues when porting drivers to ia64.

But knowing the dma masks in use on specific platforms might allow
folks to disable DMA_ZONE (like ia64 since it's always guarateed
either a SWIOTLB or real IOMMU).

Any other uses?

thanks,
grant

>
> - R.
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