dmaengine: ptdma: fix concurrency issue with multiple dma transfer

The command should be submitted only if the engine is idle,
for this, the next available descriptor is checked and set the flag
to false in case the descriptor is non-empty.

Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Link: https://lore.kernel.org/r/1643814880-3882-2-git-send-email-Sanju.Mehta@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c
index c9e52f6f2f50fe41f2e631dec661f50d9b2d9044..e38dca42239121b30f7f9f2dc7d57ea91f4720d5 100644 (file)
--- a/drivers/dma/ptdma/ptdma-dmaengine.c
+++ b/drivers/dma/ptdma/ptdma-dmaengine.c
@@ -233,9 +233,14 @@ static void pt_issue_pending(struct dma_chan *dma_chan)
        struct pt_dma_chan *chan = to_pt_chan(dma_chan);
        struct pt_dma_desc *desc;
        unsigned long flags;
+       bool engine_is_idle = true;
 
        spin_lock_irqsave(&chan->vc.lock, flags);
 
+       desc = pt_next_dma_desc(chan);
+       if (desc)
+               engine_is_idle = false;
+
        vchan_issue_pending(&chan->vc);
 
        desc = pt_next_dma_desc(chan);
@@ -243,7 +248,7 @@ static void pt_issue_pending(struct dma_chan *dma_chan)
        spin_unlock_irqrestore(&chan->vc.lock, flags);
 
        /* If there was nothing active, start processing */
-       if (desc)
+       if (engine_is_idle)
                pt_cmd_callback(desc, 0);
 }