Re: [PATCH 1/1] unify DMA_..BIT_MASK definitions: v3.1

Jeremy Fitzhardinge
2007-10-05T22:33:09Z

Andrew Morton wrote:
> Well yes, but DMA_BIT_MASK(0) invokes undefined behaviour, generates a
> compiler warning and evaluates to 0xffffffffffffffff (with my setup).
>
> That won't be a problem in practice, but it is strictly wrong and doesn't set
> a good exmaple for the children ;)
>

It's interesting that it doesn't seem to be possible to define this
without invoking some undefined behaviour. But a device that supports 0
bits of DMA address probably isn't terribly concerned about this - it's
certainly better than making 64 bit masks warty.

J