Re: [PATCH][1/3] ppc32: add 440ep support
From: Paul Mackerras
Date: Wed Jul 27 2005 - 18:06:38 EST
Andrew Morton writes:
> Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > +static u64 dma_mask = 0xffffffffULL;
>
> I'm sure you're totally uninterested in this, but the above will probably
> generate warnings on (say) ppc64, where u64 is implemented as unsigned
> long.
>
> I usually chuck a simple `-1' in there and the compiler always gets it
> right, regardless of signedness and size and architecture.
Umm, I think we actually want 2^32-1 not -1, don't we? In which case
I think Matt's code is what we have to have.
I tried a little test compile with gcc 4.0 with -m64 -Wall and it
didn't generate a warning with the 0xffffffffULL constant.
Paul.
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