Hello, Arnd Bergmann wrote: > On Friday 15 May 2009, Tejun Heo wrote: >> FUJITA Tomonori wrote: >>> Can libata call dma_supported() per device to decide DMA or PIO mode? >>> Then, we can solve this problem by add dummy DMA API (just calls BUG) >>> on such architectures, without Kconfig magic or adding ifdef (like the >>> old ide stack does), I think. > > That would be the !CONFIG_PCI half of the old > include/asm-generic/dma-mapping.h file that you just removed, > right? > > In general, I'd prefer keeping the asm-generic/dma-mapping-broken.h > implementation that gives us a compile-time error, but maybe there > is an even better option based on the mn10300 implementation which > basically pretends everything works with just page_to_phys() mappings. Don't know much history here but I don't wanna sprinkle ifdefs around in libata so I would much prefer dummy implementation which doesn't fail compile. >> Sure it can. Which specific drivers are we talking about? > > The main problem is libata-core.c, which references DMA mapping > API calls that are only implemented on architectures setting > CONFIG_HAS_DMA. Yeah, sure, libata-core is used by every driver but I was wondering whether only SFF drivers are of interest or there are others. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
