[PATCH v2] dmaengine: xgene-dma: Disable memcpy operation due to performance drop

From: Rameshwar Prasad Sahu
Date: Thu Oct 08 2015 - 05:07:37 EST


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 | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
index 8d57b1b..cd38022 100644
--- a/drivers/dma/xgene-dma.c
+++ b/drivers/dma/xgene-dma.c
@@ -1707,7 +1707,6 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
dma_cap_zero(dma_dev->cap_mask);

/* Set DMA device capability */
- dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
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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