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.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/