Hi Vinod, On Mon, Oct 12, 2015 at 7:53 PM, Vinod Koul <vinod.koul@xxxxxxxxx> wrote: > On Fri, Oct 09, 2015 at 10:08:32PM +0530, Rameshwar Sahu wrote: >> Hi Vinod, >> >> On Fri, Oct 9, 2015 at 9:42 PM, Vinod Koul <vinod.koul@xxxxxxxxx> wrote: >> > On Thu, Oct 08, 2015 at 02:36:57PM +0530, 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 | 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); >> > >> > This will not work. Still clients can invoke memcpy operation. You need to >> > remove the callback >> >> Got it, instead of removing the callback registration can we keep it >> inside the condition like.. >> >> if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) >> dma_dev->device_prep_dma_memcpy = xgene_dma_prep_memcpy; > > But the code is dead and will not be tested and hence not maintained. I do > not see a reason to keep dead code in kernel Got it, I will remove the memcpy offload support and will send another patch for review. > > -- > ~Vinod -- 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
