Hi Dirk,
Thank you for the patch.
On Fri, Apr 12, 2019 at 07:29:13AM +0200, Dirk Behme wrote:
> 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>
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.8+
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> 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);
--
Regards,
Laurent Pinchart
