MLK-22284-2 dmaengine: fsl-edma-v3: check dma description before register touch

Check dma desscription firstly to ignore any unexpected interrupt
after channel terminate, otherwise, still have chance to touch channel
register whose power has been already off.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reviewed-by: S.j. Wang <shengjiu.wang@nxp.com>
(cherry picked from commit fd073e017e317006a4c254ca5ae3ea17b6f32502)

diff --git a/drivers/dma/fsl-edma-v3.c b/drivers/dma/fsl-edma-v3.c
index 1d63c68..3f69dd3 100644 (file)
--- a/drivers/dma/fsl-edma-v3.c
+++ b/drivers/dma/fsl-edma-v3.c
@@ -708,20 +708,20 @@ static irqreturn_t fsl_edma3_tx_handler(int irq, void *dev_id)
        unsigned int intr;
        void __iomem *base_addr;
 
+       spin_lock(&fsl_chan->vchan.lock);
+
+       /* Ignore this interrupt since channel has been disabled already */
+       if (!fsl_chan->edesc)
+               goto irq_handled;
+
        base_addr = fsl_chan->membase;
 
        intr = readl(base_addr + EDMA_CH_INT);
        if (!intr)
-               return IRQ_NONE;
+               goto irq_handled;
 
        writel(1, base_addr + EDMA_CH_INT);
 
-       spin_lock(&fsl_chan->vchan.lock);
-
-       /* Ignore this interrupt since channel has been disabled already */
-       if (!fsl_chan->edesc)
-               goto irq_handled;
-
        if (!fsl_chan->edesc->iscyclic) {
                fsl_edma3_get_realcnt(fsl_chan);
                list_del(&fsl_chan->edesc->vdesc.node);