dmaengine: ste_dma40: Only calculate residue if txstate exists.

There is no point calculating the residue if there is
no txstate to store the value.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 6fb8307468ab60b847dab3c21f2899cd99876c69..378cc47aa63ab6b130a0aeaeaa07e0bfa9c4a57f 100644 (file)
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -2588,7 +2588,7 @@ static enum dma_status d40_tx_status(struct dma_chan *chan,
        }
 
        ret = dma_cookie_status(chan, cookie, txstate);
-       if (ret != DMA_COMPLETE)
+       if (ret != DMA_COMPLETE && txstate)
                dma_set_residue(txstate, stedma40_residue(chan));
 
        if (d40_is_paused(d40c))