Re: [RFC] AGP initial support for chipset flushing..

From: Dave Airlie
Date: Mon Oct 29 2007 - 15:52:56 EST



>
> In this case, we're performing basically a dma_sync*(...DMA_TO_DEVICE)
> right? 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?

Not that I can think off, but I don't work for the company who screwed up
the coherency :-), and I don't have the docs, so please investigate for me
;-)

> 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.

Again I'm trying to workaround broken BIOS.. nothing I can do.

Dave.
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