On Fri, May 7, 2010 at 8:43 PM, Linus Walleij <linus.ml.walleij@xxxxxxxxx> wrote: > 2010/5/7 Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx>: >> Or let me put it another way - if people are happy for Linux to support >> new ARM CPU architectures, but with very little attention given to DMA >> support on those architectures, then feel free to box the ARM platforms >> into a corner on DMA support - but on the understanding that _you_ will >> have to deal with the DMA API breakage on those architectures yourself. >> Because with ARM platforms not having DMA support, there's absolutely >> no way to run any checks what so ever on DMA when the CPU architecture >> support is created. > > I'm doing the best I can to meet exactly this goal. The changes done in > the DMA engine were done towards the end of making the DMA > engine support *any* DMA controller for the PrimeCells, with due respect, I think DMA Engine API is very restricting. And it is not just the 'async' character of it but also some desirable features like Circular-Linked-Buffer are missing. It may be good enough for Mem->Mem but is found wanting for Mem<->Dev transfers. I would like to see some new API defined that address reasonable requirements of extant platform specific implementations. > So now I guess I have to make it tick on the block known as PL080/PL081 > as well, and I'll have a try at it. I always hoped the pl080 core would be segregated out of S3C implementation, but for some new common DMA API. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
