Messages in this thread Patch in this message | | | From | Rameshwar Prasad Sahu <> | Subject | [PATCH] dmaengine: xgene-dma: Disable memcpy operation due to performance drop | Date | Thu, 8 Oct 2015 13:55:16 +0530 |
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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@apm.com> --- 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 -- 1.8.2.1
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