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@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 Cc: stable@vger.kernel.org # v4.8+ --- Note: Patch done against mainline v5.0
Changes in v2: None
Changes in v3: Move reading rchan into the spin lock protection.
drivers/dma/sh/rcar-dmac.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 2b4f25698169..54810ffd95e2 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -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);