[PATCH V2 resend 2/7] dmaengine/dw_dmac: Enable resubmission from callback routine.

From: Viresh Kumar
Date: Tue Apr 26 2011 - 01:39:51 EST


Resubmission of new transfer must be allowed from callbacks. For this release
lock before calling callback routine and enable them again.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxx>
---
drivers/dma/dw_dmac.c | 10 ++++------
1 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 4f4df9f..dbe8203 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -197,8 +197,8 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
static void
dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc)
{
- dma_async_tx_callback callback;
- void *param;
+ dma_async_tx_callback callback = NULL;
+ void *param = NULL;
struct dma_async_tx_descriptor *txd = &desc->txd;
struct dw_desc *child;

@@ -238,12 +238,10 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc)
}
}

- /*
- * The API requires that no submissions are done from a
- * callback, so we don't need to drop the lock here
- */
+ spin_unlock_irqrestore(&dwc->lock, dw->flags);
if (callback)
callback(param);
+ spin_lock_irqsave(&dwc->lock, dw->flags);
}

static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
--
1.7.2.2

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