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Subject[PATCH v3 8/9] dmaengine: dw: return immediately from IRQ when DMA isn't in use
Date
There is no need to bother the hardware when all channels are idle. We have not
to get any interrupts.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/dma/dw/core.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 7067b6d..8b20930 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -622,12 +622,17 @@ static void dw_dma_tasklet(unsigned long data)
static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
{
struct dw_dma *dw = dev_id;
- u32 status = dma_readl(dw, STATUS_INT);
+ u32 status;

+ /* Check if we have any interrupt from the DMAC which is not in use */
+ if (!dw->in_use)
+ return IRQ_NONE;
+
+ status = dma_readl(dw, STATUS_INT);
dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);

/* Check if we have any interrupt from the DMAC */
- if (!status || !dw->in_use)
+ if (!status)
return IRQ_NONE;

/*
--
2.6.2


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