From 9bd257181fd5c996d922e9991500ad27987cfbf4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nuno=20S=C3=A1?= Date: Tue, 4 Nov 2025 16:22:25 +0000 Subject: [PATCH] dma: dma-axi-dmac: fix SW cyclic transfers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If 'hw_cyclic' is false we should still be able to do cyclic transfers in "software". That was not working for the case where 'desc->num_sgs' is 1 because 'chan->next_desc' is never set with the current desc which means that the cyclic transfer only runs once and in the next SOT interrupt we do nothing since vchan_next_desc() will return NULL. Fix it by setting 'chan->next_desc' as soon as we get a new desc via vchan_next_desc(). Fixes: 0e3b67b348b8 ("dmaengine: Add support for the Analog Devices AXI-DMAC DMA controller") Signed-off-by: Nuno Sá base-commit: 398035178503bf662281bbffb4bebce1460a4bc5 change-id: 20251104-axi-dmac-fixes-and-improvs-e3ad512a329c Acked-by: Michael Hennerich Link: https://patch.msgid.link/20251104-axi-dmac-fixes-and-improvs-v1-1-3e6fd9328f72@analog.com Signed-off-by: Vinod Koul --- drivers/dma/dma-axi-dmac.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index 5b06b0dc67ee..e22639822045 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -247,6 +247,7 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan) return; list_move_tail(&vdesc->node, &chan->active_descs); desc = to_axi_dmac_desc(vdesc); + chan->next_desc = desc; } sg = &desc->sg[desc->num_submitted]; @@ -265,8 +266,6 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan) else chan->next_desc = NULL; flags |= AXI_DMAC_FLAG_LAST; - } else { - chan->next_desc = desc; } sg->hw->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);