Commit 907bd68a authored Apr 12, 2019 by Dirk Behme Committed by Vinod Koul Apr 23, 2019

dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid



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: 3544d287 ("dmaengine: rcar-dmac: use result of updated get_residue in tx_status")
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Achim Dahlhoff <Achim.Dahlhoff@de.bosch.com>
Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Yao Lihua <ylhuajnu@outlook.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Vinod Koul <vkoul@kernel.org>

parent f1473847

drivers/dma/sh/rcar-dmac.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1368,6 +1368,7 @@ static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan,
		enum dma_status status;
		unsigned long flags;
		unsigned int residue;
		bool cyclic;

		status = dma_cookie_status(chan, cookie, txstate);
		if (status == DMA_COMPLETE \|\| !txstate)
		@@ -1375,10 +1376,11 @@ static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan,

		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);

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