Messages in this thread | | | Subject | Re: [RFC] AGP initial support for chipset flushing.. | From | Keith Packard <> | Date | Mon, 29 Oct 2007 13:12:58 -0700 |
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On Mon, 2007-10-29 at 12:47 -0700, Jesse Barnes wrote:
> In this case, we're performing basically a dma_sync*(...DMA_TO_DEVICE) > right?
But this is just for the GPU; every other DMA device in the system is cache-coherent.
> Can we be sure that a single flush is sufficient? Is there any > window between when we flush and when we start accessing memory with > the device that we could get into more caching trouble?
An uncached write to this page will not complete until the buffers are completely flushed.
> Looks reasonable, I'm not sure we can do much better. The only concern > I have is that allocating some more PCI space like that may end up > clobbering some *other* hidden BIOS mapping, but there's not a whole > lot we can do about that.
This isn't a hidden mapping; the i965 doesn't allocate space for it in the BIOS.
-- keith.packard@intel.com [unhandled content-type:application/pgp-signature]
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