diff options
| -rw-r--r-- | drivers/dma/qcom/bam_dma.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 8fbf175fdcc7..57c5cc51f862 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -690,7 +690,21 @@ 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; } |