Merge remote-tracking branch 'remotes/fslc/4.9-2.3.x-imx' into toradex_4.9-2.3.x-imx-next

Conflicts:
	sound/soc/codecs/sgtl5000.c
	sound/soc/fsl/imx-sgtl5000.c

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index 6497f5283e3b..81acbde13394 100644
--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -686,7 +686,21 @@ static int bam_dma_terminate_all(struct dma_chan *chan)
 
 	/* remove all transactions, including active transaction */
 	spin_lock_irqsave(&bchan->vc.lock, flag);
+	/*
+	 * If we have transactions queued, then some might be committed to the
+	 * hardware in the desc fifo.  The only way to reset the desc fifo is
+	 * to do a hardware reset (either by pipe or the entire block).
+	 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
+	 * pipe.  If the pipe is left disabled (default state after pipe reset)
+	 * and is accessed by a connected hardware engine, a fatal error in
+	 * the BAM will occur.  There is a small window where this could happen
+	 * with bam_chan_init_hw(), but it is assumed that the caller has
+	 * stopped activity on any attached hardware engine.  Make sure to do
+	 * this first so that the BAM hardware doesn't cause memory corruption
+	 * by accessing freed resources.
+	 */
 	if (bchan->curr_txd) {
+		bam_chan_init_hw(bchan, bchan->curr_txd->dir);
 		list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
 		bchan->curr_txd = NULL;
 	}