Re: [RFC] generic device DMA implementation

[Arjan van de Ven]

On Fri, 2002-12-06 at 23:26, James Bottomley wrote:
> [e-mail] said:
> > 	This makes me lean infinitesmally more toward a parameter to
> > dma_alloc rather than a separate dma_alloc_not_necessarily_consistent
> > function, because if there ever are other dma_alloc variations that we
> > want to support, it is more likely that there may be overlap between
> > the users of those features and then the number of different function
> > calls would have to grow exponentially (or we might then talk about
> > changing the API again, which is not the end of the world, but is
> > certainly more difficult than not having to do so). 
> 
> I think I like this.
> 
> how about dma_alloc to take two flags
> 
> DRIVER_SUPPORTS_CONSISTENT_ONLY
> 
> and
> DRIVER_SUPPORTS_CONSISTENT_ONLY
> DRIVER_SUPPORTS_NON_CONSISTENT
> 

I rather like Dave's suggestion. I wouldn't want to type
DRIVER_SUPPORTS_CONSISTENT_ONLY a few dozen times for example... sure
you can do that internally but exposing it to drivers... why ?