[PATCH 05/12] ARM: mach-s5pv210: Setup consistent dma size at boot time
Pavel Machek
pavel at ucw.cz
Fri Aug 12 11:09:30 EDT 2011
On Thu 2011-08-11 14:08:09, Tixy wrote:
> On Thu, 2011-08-11 at 14:50 +0200, Pavel Machek wrote:
> >
> > > -#define CONSISTENT_DMA_SIZE (SZ_8M + SZ_4M + SZ_2M)
> > ...
> > > + init_consistent_dma_size(14 << 20);
> >
> > Are you sure that's equivalent?
>
> Yes. From include/asm-generic/sizes.h
>
> #define SZ_2M 0x00200000
> #define SZ_4M 0x00400000
> #define SZ_8M 0x00800000
>
> The max DMA size seems to be have been defined as 14MB at some point and
> several platforms define the size to be this value, but in different
> ways:
>
> SZ_16M - SZ_2M
> SZ_8M + SZ_4M + SZ_2M
> 14 << 20
>
> I chose to use just one for consistency, and (14 << 20) seemed clearer
> to me.
I missed the "4" in "14". Doing 14 *1024*1024 would be more usual way
of writing this...
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
More information about the linux-arm-kernel
mailing list