dmaengine: jz4780: Kill tasklets before unregistering the device

Tasklets may have been scheduled as a result of an earlier interrupt
that could still be running. Kill them before unregistering the
device.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dma-jz4780.c

@@ -866,9 +866,15 @@ err_free_irq:
 static int jz4780_dma_remove(struct platform_device *pdev)
 {
 	struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
+	int i;
 
 	of_dma_controller_free(pdev->dev.of_node);
+
 	free_irq(jzdma->irq, jzdma);
+
+	for (i = 0; i < JZ_DMA_NR_CHANNELS; i++)
+		tasklet_kill(&jzdma->chan[i].vchan.task);
+
 	dma_async_device_unregister(&jzdma->dma_device);
 	return 0;
 }