dmaengine: imx-dma: fix callback path in tasklet

commit fcaaba6c7136fe47e5a13352f99a64b019b6d2c5 upstream.

We need to free the ld_active list head before jumping into the callback
routine. Otherwise the callback could run into issue_pending and change
our ld_active list head we just going to free. This will run the channel
list into an currupted and undefined state.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index a265226ff629d9ae097561509a02226d449a2f45..d0f0fafff37162779cf17670ddff3e4df8caace3 100644 (file)
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -563,13 +563,11 @@ static void imxdma_tasklet(unsigned long data)
 
        if (list_empty(&imxdmac->ld_active)) {
                /* Someone might have called terminate all */
-               goto out;
+               spin_unlock_irqrestore(&imxdma->lock, flags);
+               return;
        }
        desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, node);
 
-       if (desc->desc.callback)
-               desc->desc.callback(desc->desc.callback_param);
-
        /* If we are dealing with a cyclic descriptor keep it on ld_active
         * and dont mark the descripor as complete.
         * Only in non-cyclic cases it would be marked as complete
@@ -597,6 +595,10 @@ static void imxdma_tasklet(unsigned long data)
        }
 out:
        spin_unlock_irqrestore(&imxdma->lock, flags);
+
+       if (desc->desc.callback)
+               desc->desc.callback(desc->desc.callback_param);
+
 }
 
 static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,