On Thu, Oct 8, 2015 at 2:23 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Thursday 08 October 2015 13:55:16 Rameshwar Prasad Sahu wrote: >> The DMA engine supports memory copy, RAID5 XOR, RAID6 PQ, and other >> computations. But the bandwidth of the entire DMA engine is shared >> among all channels. This patch re-configures operations availability >> such that one can achieve maximum performance for XOR and PQ >> computation by removing the memory offload operations. >> >> Signed-off-by: Rameshwar Prasad Sahu <rsahu@xxxxxxx> >> --- >> drivers/dma/xgene-dma.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c >> index 8d57b1b..2998fcb 100644 >> --- a/drivers/dma/xgene-dma.c >> +++ b/drivers/dma/xgene-dma.c >> @@ -154,6 +154,7 @@ >> #define XGENE_DMA_MAX_XOR_SRC 5 >> #define XGENE_DMA_16K_BUFFER_LEN_CODE 0x0 >> #define XGENE_DMA_INVALID_LEN_CODE 0x7800000000000000ULL >> +#undef XGENE_DMA_MEMCPY_ENABLE >> >> /* X-Gene DMA descriptor error codes */ >> #define ERR_DESC_AXI 0x01 >> @@ -1707,7 +1708,9 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan, >> dma_cap_zero(dma_dev->cap_mask); >> >> /* Set DMA device capability */ >> +#ifdef XGENE_DMA_MEMCPY_ENABLE >> dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); >> +#endif >> dma_cap_set(DMA_SG, dma_dev->cap_mask); >> >> /* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR > > I don't see what the #ifdef gains you here when the setting is > hardcoded. Why not just remove that DMA_MEMCPY capability completely > if you don't want to use it? Okay Arnd, > > Arnd > -- > To unsubscribe from this list: send the line "unsubscribe dmaengine" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
