dma: dw: allow shared interrupts

In the PC world is quite possible that devices are sharing the same interrupt
line. The patch prepares dw_dmac driver to such cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 1ed9a9c..6932645 100644 (file)
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -650,10 +650,13 @@ 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;
+       u32 status = dma_readl(dw, STATUS_INT);
 
-       dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__,
-                       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)
+               return IRQ_NONE;
 
        /*
         * Just disable the interrupts. We'll turn them back on in the
@@ -1566,8 +1569,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
        /* Disable BLOCK interrupts as well */
        channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 
-       err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt, 0,
-                              "dw_dmac", dw);
+       err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt,
+                              IRQF_SHARED, "dw_dmac", dw);
        if (err)
                return err;