dmaengine: coh901318: kill the tasklets upon exit

drivers should ensure that tasklets are killed, so that they can't be
run after driver remove is executed.

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index ba044d4..9b86c3e 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -2758,6 +2758,21 @@
 	coh901318_pool_destroy(&base->pool);
 	return err;
 }
+static void coh901318_base_remove(struct coh901318_base *base, const int *pick_chans)
+{
+	int chans_i;
+	int i = 0;
+	struct coh901318_chan *cohc;
+
+	for (chans_i = 0; pick_chans[chans_i] != -1; chans_i += 2) {
+		for (i = pick_chans[chans_i]; i <= pick_chans[chans_i+1]; i++) {
+			cohc = &base->chans[i];
+
+			tasklet_kill(&cohc->tasklet);
+		}
+	}
+
+}
 
 static int coh901318_remove(struct platform_device *pdev)
 {
@@ -2765,6 +2780,9 @@
 
 	devm_free_irq(&pdev->dev, base->irq, base);
 
+	coh901318_base_remove(base, dma_slave_channels);
+	coh901318_base_remove(base, dma_memcpy_channels);
+
 	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&base->dma_memcpy);
 	dma_async_device_unregister(&base->dma_slave);