[PATCH 4.14 18/53] dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid

[Greg Kroah-Hartman]

From: Dirk Behme <dirk.behme@xxxxxxxxxxxx>

commit 907bd68a2edc491849e2fdcfe52c4596627bca94 upstream.

Having a cyclic DMA, a residue 0 is not an indication of a completed
DMA. In case of cyclic DMA make sure that dma_set_residue() is called
and with this a residue of 0 is forwarded correctly to the caller.

Fixes: 3544d2878817 ("dmaengine: rcar-dmac: use result of updated get_residue in tx_status")
Signed-off-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx>
Signed-off-by: Achim Dahlhoff <Achim.Dahlhoff@xxxxxxxxxxxx>
Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@xxxxxxxxxxx>
Signed-off-by: Yao Lihua <ylhuajnu@xxxxxxxxxxx>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v4.8+
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/dma/sh/rcar-dmac.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1332,6 +1332,7 @@ static enum dma_status rcar_dmac_tx_stat
 	enum dma_status status;
 	unsigned long flags;
 	unsigned int residue;
+	bool cyclic;
 
 	status = dma_cookie_status(chan, cookie, txstate);
 	if (status == DMA_COMPLETE || !txstate)
@@ -1339,10 +1340,11 @@ static enum dma_status rcar_dmac_tx_stat
 
 	spin_lock_irqsave(&rchan->lock, flags);
 	residue = rcar_dmac_chan_get_residue(rchan, cookie);
+	cyclic = rchan->desc.running ? rchan->desc.running->cyclic : false;
 	spin_unlock_irqrestore(&rchan->lock, flags);
 
 	/* if there's no residue, the cookie is complete */
-	if (!residue)
+	if (!residue && !cyclic)
 		return DMA_COMPLETE;
 
 	dma_set_residue(txstate, residue);