dmaengine: at_xdmac: wait for in-progress transaction to complete after pausing a channel

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index c39000b9980a..ed8a576cee7b 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1136,9 +1136,14 @@ static int at_xdmac_device_pause(struct dma_chan *chan)
 
         dev_dbg(chan2dev(chan), "%s\n", __func__);
 
+        if (test_and_set_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status))
+                return 0;
+
         spin_lock_bh(&atchan->lock);
         at_xdmac_write(atxdmac, AT_XDMAC_GRWS, atchan->mask);
-        set_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
+        while (at_xdmac_chan_read(atchan, AT_XDMAC_CC)
+               & (AT_XDMAC_CC_WRIP | AT_XDMAC_CC_RDIP))
+                cpu_relax();
         spin_unlock_bh(&atchan->lock);
 
         return 0;