| Message ID | 20190412052914.16006-1-dirk.behme@de.bosch.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | [v3,1/2] dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid | expand |
Hi Dirk-san, > From: Dirk Behme, Sent: Friday, April 12, 2019 2:29 PM > > 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+ > --- Thank you for the patch! Since cyclic transfers will not stop even if the residue is 0, I agree this driver should not return DMA_COMPLETE (transaction completed). So, Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Best regards, Yoshihiro Shimoda
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@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+ Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > 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);
On 12-04-19, 07:29, 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. Applied both, thanks
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);
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(-)