Re: [PATCH 3/3] MIPS: DMA: Add plat_extra_sync_for_cpu()

From: Thomas Bogendoerfer
Date: Thu Sep 09 2010 - 17:33:34 EST


On Thu, Sep 09, 2010 at 10:10:00AM -0700, David Daney wrote:
> On 09/08/2010 04:02 PM, Kevin Cernekee wrote:
>> On noncoherent processors with a readahead cache, an extra platform-
>> specific invalidation is required during the dma_sync_*_for_cpu()
>> operations to keep drivers from seeing stale prefetched data.
>
> But as far as I can see, none of your plat_extra_sync_for_cpu() do anything.
>
> Perhaps adding this hook should be deferred until there is actually a user.

looks like this is doing what the non_coherent_r10000 case does. So IMHO
either which make non_coheren check more generic or could use the new
plat_sync thingie for IP28 and other non coherent r10k boxes.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea. [ RFC1925, 2.3 ]
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