dma: pl330: split off common code to give back descriptors

This patch adds __pl330_giveback_descs which give back descriptors when fails
allocating descriptors. It requires to eliminate duplication for
pl330_prep_dma_sg which will be added later.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Acked-by : Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 23 insertions, 15 deletions

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index d8c10449fb42..facd23afaceb 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2814,6 +2814,28 @@ pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst,
         return &desc->txd;
 }
 
+static void __pl330_giveback_desc(struct dma_pl330_dmac *pdmac,
+                                  struct dma_pl330_desc *first)
+{
+        unsigned long flags;
+        struct dma_pl330_desc *desc;
+
+        if (!first)
+                return;
+
+        spin_lock_irqsave(&pdmac->pool_lock, flags);
+
+        while (!list_empty(&first->node)) {
+                desc = list_entry(first->node.next,
+                                struct dma_pl330_desc, node);
+                list_move_tail(&desc->node, &pdmac->desc_pool);
+        }
+
+        list_move_tail(&first->node, &pdmac->desc_pool);
+
+        spin_unlock_irqrestore(&pdmac->pool_lock, flags);
+}
+
 static struct dma_async_tx_descriptor *
 pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                 unsigned int sg_len, enum dma_transfer_direction direction,
@@ -2822,7 +2844,6 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
         struct dma_pl330_desc *first, *desc = NULL;
         struct dma_pl330_chan *pch = to_pchan(chan);
         struct scatterlist *sg;
-        unsigned long flags;
         int i;
         dma_addr_t addr;
 
@@ -2842,20 +2863,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                         dev_err(pch->dmac->pif.dev,
                                 "%s:%d Unable to fetch desc\n",
                                 __func__, __LINE__);
-                        if (!first)
-                                return NULL;
-
-                        spin_lock_irqsave(&pdmac->pool_lock, flags);
-
-                        while (!list_empty(&first->node)) {
-                                desc = list_entry(first->node.next,
-                                                struct dma_pl330_desc, node);
-                                list_move_tail(&desc->node, &pdmac->desc_pool);
-                        }
-
-                        list_move_tail(&first->node, &pdmac->desc_pool);
-
-                        spin_unlock_irqrestore(&pdmac->pool_lock, flags);
+                        __pl330_giveback_desc(pdmac, first);
 
                         return NULL;
                 }