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author | Otavio Salvador <otavio@ossystems.com.br> | 2019-12-19 00:14:33 -0300 |
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committer | GitHub <noreply@github.com> | 2019-12-19 00:14:33 -0300 |
commit | fa8a03bec68d9ef89da72277bd3501ed3daa6217 (patch) | |
tree | 3d3218332bcb34cb0afa01d6ad996058a3dbcb77 /drivers/dma/qcom/bam_dma.c | |
parent | 6b774eec1f9d3064e9b33634dfa99d5666d0a73a (diff) | |
parent | 1ddf624b0b268fdc0b80b1de618b98f8d117afea (diff) |
Merge pull request #55 from toradex/4.14-2.0.x-imx
4.14 2.0.x imx
Diffstat (limited to 'drivers/dma/qcom/bam_dma.c')
-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; } |