| Message ID | 1443559488-2416-5-git-send-email-hamzahfrq.sub@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Tue, Sep 29, 2015 at 10:44:46PM +0200, hamzahfrq.sub@gmail.com wrote: > From: Muhammad Hamza Farooq <mfarooq@visteon.com> > > Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com> > --- > drivers/dma/sh/rcar-dmac.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c > index 6c806d0..0b5a367 100644 > --- a/drivers/dma/sh/rcar-dmac.c > +++ b/drivers/dma/sh/rcar-dmac.c > @@ -1258,6 +1258,10 @@ static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan, > residue = rcar_dmac_chan_get_residue(rchan, cookie); > spin_unlock_irqrestore(&rchan->lock, flags); > > + /* if there's no residue, the cookie is complete */ > + if (!residue) > + return DMA_COMPLETE; > + why would we get this, you should not be here if the status is complete and exited before you checked the status
Hi Vinod, On Monday 12 October 2015 20:42:32 Vinod Koul wrote: > On Tue, Sep 29, 2015 at 10:44:46PM +0200, hamzahfrq.sub@gmail.com wrote: > > From: Muhammad Hamza Farooq <mfarooq@visteon.com> > > > > Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com> > > --- > > > > drivers/dma/sh/rcar-dmac.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c > > index 6c806d0..0b5a367 100644 > > --- a/drivers/dma/sh/rcar-dmac.c > > +++ b/drivers/dma/sh/rcar-dmac.c > > @@ -1258,6 +1258,10 @@ static enum dma_status rcar_dmac_tx_status(struct > > dma_chan *chan,> > > residue = rcar_dmac_chan_get_residue(rchan, cookie); > > spin_unlock_irqrestore(&rchan->lock, flags); > > > > + /* if there's no residue, the cookie is complete */ > > + if (!residue) > > + return DMA_COMPLETE; > > + > > why would we get this, you should not be here if the status is complete and > exited before you checked the status The status check is a software check, while the residue check reads hardware registers. The hardware might have complete the transfer but the interrupt handler might not have had a chance to run yet. Is it valid from a DMA engine API point of view to return a DMA_IN_PROGRESS status with a 0 residue ?
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 6c806d0..0b5a367 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -1258,6 +1258,10 @@ static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan, residue = rcar_dmac_chan_get_residue(rchan, cookie); spin_unlock_irqrestore(&rchan->lock, flags); + /* if there's no residue, the cookie is complete */ + if (!residue) + return DMA_COMPLETE; + dma_set_residue(txstate, residue); return status;