dmaengine: pl330: Handle xferred count if DMAMOV hasn't finished

After executing DMAGO it's possible that a request can come in for the
current xferred count, but if that happens too soon then DMAMOV SAR/DAR
may not have yet completed. If that happens, we should explicitly return 0
since nothing has been transferred yet.

Signed-off-by: Stephen Barber <smbarber@chromium.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 030fe05ed43b1e99a63644324fb30305198c62ce..458a712a9da1fded2d99d6f1d59806386a2dec25 100644 (file)
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2263,6 +2263,11 @@ static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch,
        }
        pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
        pm_runtime_put_autosuspend(pl330->ddma.dev);
+
+       /* If DMAMOV hasn't finished yet, SAR/DAR can be zero */
+       if (!val)
+               return 0;
+
        return val - addr;
 }