dmaengine: mv_xor_v2: do not use descriptors not acked by async_tx

Descriptors that have not been acknowledged by the async_tx layer
should not be re-used, so this commit adjusts the implementation of
mv_xor_v2_prep_sw_desc() to skip descriptors for which
async_tx_test_ack() is false.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index bdfb36ecff81b2b081803c8d9a0723fb4847f401..cb60e7c4aa169f61a3b2dd976d9ab8ab87a07265 100644 (file)
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -344,6 +344,7 @@ static struct mv_xor_v2_sw_desc     *
 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
 {
        struct mv_xor_v2_sw_desc *sw_desc;
+       bool found = false;
 
        /* Lock the channel */
        spin_lock_bh(&xor_dev->lock);
@@ -355,19 +356,23 @@ mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
                return NULL;
        }
 
-       /* get a free SW descriptor from the SW DESQ */
-       sw_desc = list_first_entry(&xor_dev->free_sw_desc,
-                                  struct mv_xor_v2_sw_desc, free_list);
+       list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
+               if (async_tx_test_ack(&sw_desc->async_tx)) {
+                       found = true;
+                       break;
+               }
+       }
+
+       if (!found) {
+               spin_unlock_bh(&xor_dev->lock);
+               return NULL;
+       }
+
        list_del(&sw_desc->free_list);
 
        /* Release the channel */
        spin_unlock_bh(&xor_dev->lock);
 
-       /* set the async tx descriptor */
-       dma_async_tx_descriptor_init(&sw_desc->async_tx, &xor_dev->dmachan);
-       sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
-       async_tx_ack(&sw_desc->async_tx);
-
        return sw_desc;
 }
 
@@ -785,8 +790,15 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 
        /* add all SW descriptors to the free list */
        for (i = 0; i < MV_XOR_V2_DESC_NUM; i++) {
-               xor_dev->sw_desq[i].idx = i;
-               list_add(&xor_dev->sw_desq[i].free_list,
+               struct mv_xor_v2_sw_desc *sw_desc =
+                       xor_dev->sw_desq + i;
+               sw_desc->idx = i;
+               dma_async_tx_descriptor_init(&sw_desc->async_tx,
+                                            &xor_dev->dmachan);
+               sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
+               async_tx_ack(&sw_desc->async_tx);
+
+               list_add(&sw_desc->free_list,
                         &xor_dev->free_sw_desc);
        }