From 63ab76dbbdb8657e24645b7311ec3911a41039b5 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 5 Sep 2017 10:16:37 +0200 Subject: [PATCH] dmaengine: axi-dmac: Only use hardware cyclic mode for single segment transfers In hardware cyclic mode the submitted segment is repeated. This means hardware cyclic mode can only be used if the transfer has a single segment. Signed-off-by: Lars-Peter Clausen Signed-off-by: Vinod Koul --- drivers/dma/dma-axi-dmac.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index 7f0b9aa..eb289aa 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -220,9 +220,11 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan) /* * If the hardware supports cyclic transfers and there is no callback to - * call, enable hw cyclic mode to avoid unnecessary interrupts. + * call and only a single segment, enable hw cyclic mode to avoid + * unnecessary interrupts. */ - if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback) + if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback && + desc->num_sgs == 1) flags |= AXI_DMAC_FLAG_CYCLIC; axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1); -- 2.7.4