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[2/7] dmaengine: omap-dma: complete the transfer on terminate_all

Message ID 1406660344-25307-3-git-send-email-bigeasy@linutronix.de (mailing list archive)
State Not Applicable
Headers show

Commit Message

Sebastian Sewior July 29, 2014, 6:58 p.m. UTC
The rx path of the 8250_dma user in the RX-timeout case:
- it starts the RX transfer
- if the rx-timeout interrupt occures, it dmaengine_pause() the transfer
- step two is dmaengine_terminate_all() on this channel.
- the rx interrupt occures, it does not start the RX-transfer because
  according to dmaengine_tx_status() the status of the current transfer
  is still DMA_IN_PROGRESS because the earlier dmaengine_terminate_all()
  did not reset this.

To fix this problem, the patch adds dma_cookie_complete() "complete" the
current cookie.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Vinod Koul <vinod.koul@intel.com> 
Cc: Dan Williams <dan.j.williams@intel.com> 
Cc: dmaengine@vger.kernel.org 
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/dma/omap-dma.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Sebastian Sewior July 29, 2014, 7:06 p.m. UTC | #1
On 07/29/2014 08:58 PM, Sebastian Andrzej Siewior wrote:
> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
> index b19f04f..81ede01 100644
> --- a/drivers/dma/omap-dma.c
> +++ b/drivers/dma/omap-dma.c
> @@ -970,6 +970,12 @@ static int omap_dma_terminate_all(struct omap_chan *c)
>  
>  	/* Prevent this channel being scheduled */
>  	spin_lock(&d->lock);
> +	if (!c->desc && !list_empty(&c->node)) {
> +		struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
> +
> +		if (vd)
> +			dma_cookie_complete(&vd->tx);
> +	}

Why is start of the transfer deferred to the tasklet unless it is a
periodic transfer? Couldn't it be started right away?

>  	list_del_init(&c->node);
>  	spin_unlock(&d->lock);
>  

Sebastian
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diff mbox

Patch

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index b19f04f..81ede01 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -970,6 +970,12 @@  static int omap_dma_terminate_all(struct omap_chan *c)
 
 	/* Prevent this channel being scheduled */
 	spin_lock(&d->lock);
+	if (!c->desc && !list_empty(&c->node)) {
+		struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
+
+		if (vd)
+			dma_cookie_complete(&vd->tx);
+	}
 	list_del_init(&c->node);
 	spin_unlock(&d->lock);
 
@@ -979,6 +985,7 @@  static int omap_dma_terminate_all(struct omap_chan *c)
 	 * c->desc is NULL and exit.)
 	 */
 	if (c->desc) {
+		dma_cookie_complete(&c->desc->vd.tx);
 		c->desc = NULL;
 		/* Avoid stopping the dma twice */
 		if (!c->paused)