Commit e900c30d authored Jul 22, 2015 by Ludovic Desroches Committed by Vinod Koul Aug 19, 2015

dmaengine: at_xdmac: fix bug in prep_dma_cyclic

In cyclic mode, the round chaining has been broken by the introduction
of at_xdmac_queue_desc(): AT_XDMAC_MBR_UBC_NDE is set for all descriptors
excepted for the last one. at_xdmac_queue_desc() has to be called one
more time to chain the last and the first descriptors.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Fixes: 0d0ee751 ("dmaengine: xdmac: Rework the chaining logic")
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

parent ae9c02b4

drivers/dma/at_xdmac.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -795,10 +795,7 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
		list_add_tail(&desc->desc_node, &first->descs_list);
		}

		prev->lld.mbr_nda = first->tx_dma_desc.phys;
		dev_dbg(chan2dev(chan),
		"%s: chain lld: prev=0x%p, mbr_nda=%pad\n",
		__func__, prev, &prev->lld.mbr_nda);
		at_xdmac_queue_desc(chan, prev, first);
		first->tx_dma_desc.flags = flags;
		first->xfer_size = buf_len;
		first->direction = direction;

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