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 -- ~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
