intel_mid_dma: Allow IRQ sharing

intel_mid_dma driver allows interrupt sharing. Thus it needs
to check whether IRQ source is the DMA controller and return
the appropriate IRQ return.

Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c
index 373396c..c4b8138 100644 (file)
--- a/drivers/dma/intel_mid_dma.c
+++ b/drivers/dma/intel_mid_dma.c
@@ -817,9 +817,14 @@ static void dma_tasklet2(unsigned long data)
 static irqreturn_t intel_mid_dma_interrupt(int irq, void *data)
 {
        struct middma_device *mid = data;
-       u32 status;
+       u32 tfr_status, err_status;
        int call_tasklet = 0;
 
+       tfr_status = ioread32(mid->dma_base + RAW_TFR);
+       err_status = ioread32(mid->dma_base + RAW_ERR);
+       if (!tfr_status && !err_status)
+               return IRQ_NONE;
+
        /*DMA Interrupt*/
        pr_debug("MDMA:Got an interrupt on irq %d\n", irq);
        if (!mid) {
@@ -827,19 +832,17 @@ static irqreturn_t intel_mid_dma_interrupt(int irq, void *data)
                return -EINVAL;
        }
 
-       status = ioread32(mid->dma_base + RAW_TFR);
-       pr_debug("MDMA: Status %x, Mask %x\n", status, mid->intr_mask);
-       status &= mid->intr_mask;
-       if (status) {
+       pr_debug("MDMA: Status %x, Mask %x\n", tfr_status, mid->intr_mask);
+       tfr_status &= mid->intr_mask;
+       if (tfr_status) {
                /*need to disable intr*/
-               iowrite32((status << 8), mid->dma_base + MASK_TFR);
-               pr_debug("MDMA: Calling tasklet %x\n", status);
+               iowrite32((tfr_status << 8), mid->dma_base + MASK_TFR);
+               pr_debug("MDMA: Calling tasklet %x\n", tfr_status);
                call_tasklet = 1;
        }
-       status = ioread32(mid->dma_base + RAW_ERR);
-       status &= mid->intr_mask;
-       if (status) {
-               iowrite32(MASK_INTR_REG(status), mid->dma_base + MASK_ERR);
+       err_status &= mid->intr_mask;
+       if (err_status) {
+               iowrite32(MASK_INTR_REG(err_status), mid->dma_base + MASK_ERR);
                call_tasklet = 1;
        }
        if (call_tasklet)