On Thu, 26 Aug 2010 08:16:24 -0500 "Guzman Lugo, Fernando" <fernando.lugo@xxxxxx> wrote: > >From a quick look, arch/arm/plat-omap/iovmm.c does nothing wrong about > >scatter gather chaining. arm/arm/mm/dma-mapping.c looks fine too about > >it. Maybe just defining ARCH_HAS_SG_CHAIN works? > > I can try, but it looks tricky for me. Maybe someone else can tell us why > SG chain is not supported for ARM or if there is a problem just defining > ARCH_HAS_SG_CHAIN. I suppose that nobody in ARM has been interested in the feature. It was invented to improve I/O performance with large I/O requests. No wonder embeded people aren't interested in it. fujita@rose:~/git/linux-2.6$ find arch -name 'scatterlist.h'|xargs grep HAS_SG arch/x86/include/asm/scatterlist.h:#define ARCH_HAS_SG_CHAIN arch/ia64/include/asm/scatterlist.h:#define ARCH_HAS_SG_CHAIN arch/sparc/include/asm/scatterlist.h:#define ARCH_HAS_SG_CHAIN arch/powerpc/include/asm/scatterlist.h:#define ARCH_HAS_SG_CHAIN -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
