David Gibson wrote:
> On Wed, Dec 04, 2002 at 11:47:14AM -0600, James Bottomley wrote:
>>The new DMA API allows a driver to advertise its level of consistent memory
>>compliance to dma_alloc_consistent. There are essentially two levels:
>>
>>- I only work with consistent memory, fail if I cannot get it, or
>>- I can work with inconsistent memory, try consistent first but return
>>inconsistent if it's not available.
>
>
> Do you have an example of where the second option is useful? Off hand
> the only places I can think of where you'd use a consistent_alloc()
> rather than map_single() and friends is in cases where the hardware's
> behaviour means you absolutely positively have to have consistent
> memory.
agreed, good catch. Returning inconsistent memory when you asked for
consistent makes not much sense: the programmer either knows what the
hardware wants, or the programmer is silly and should not be using
alloc_consistent anyway.
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This archive was generated by hypermail 2b29 : Sat Dec 07 2002 - 22:00:21 EST