From 02a21b79acdb48b312f1351fd7cc728e66e81149 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 4 Dec 2015 23:49:24 +0200 Subject: [PATCH] dmaengine: dw: return immediately from IRQ when DMA isn't in use 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 Acked-by: Vinod Koul Signed-off-by: Rafael J. Wysocki --- 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 7067b6ddc1db..8b20930ade98 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; /* -- 2.11.0