1 files changed, 19 insertions, 8 deletions

diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index 71fba82462cb..6be317262200 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -85,18 +85,28 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
                         enum dma_ctrl_flags flags = desc->async_tx.flags;
                         u32 src_cnt;
                         dma_addr_t addr;
+                        dma_addr_t dest;
 
+                        src_cnt = unmap->unmap_src_cnt;
+                        dest = iop_desc_get_dest_addr(unmap, iop_chan);
                         if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-                                addr = iop_desc_get_dest_addr(unmap, iop_chan);
-                                dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);
+                                enum dma_data_direction dir;
+
+                                if (src_cnt > 1) /* is xor? */
+                                        dir = DMA_BIDIRECTIONAL;
+                                else
+                                        dir = DMA_FROM_DEVICE;
+
+                                dma_unmap_page(dev, dest, len, dir);
                         }
 
                         if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-                                src_cnt = unmap->unmap_src_cnt;
                                 while (src_cnt--) {
                                         addr = iop_desc_get_src_addr(unmap,
                                                                      iop_chan,
                                                                      src_cnt);
+                                        if (addr == dest)
+                                                continue;
                                         dma_unmap_page(dev, addr, len,
                                                        DMA_TO_DEVICE);
                                 }
@@ -411,6 +421,7 @@ iop_adma_tx_submit(struct dma_async_tx_descriptor *tx)
         int slot_cnt;
         int slots_per_op;
         dma_cookie_t cookie;
+        dma_addr_t next_dma;
 
         grp_start = sw_desc->group_head;
         slot_cnt = grp_start->slot_cnt;
@@ -425,12 +436,12 @@ iop_adma_tx_submit(struct dma_async_tx_descriptor *tx)
                          &old_chain_tail->chain_node);
 
         /* fix up the hardware chain */
-        iop_desc_set_next_desc(old_chain_tail, grp_start->async_tx.phys);
+        next_dma = grp_start->async_tx.phys;
+        iop_desc_set_next_desc(old_chain_tail, next_dma);
+        BUG_ON(iop_desc_get_next_desc(old_chain_tail) != next_dma); /* flush */
 
-        /* 1/ don't add pre-chained descriptors
-         * 2/ dummy read to flush next_desc write
-         */
-        BUG_ON(iop_desc_get_next_desc(sw_desc));
+        /* check for pre-chained descriptors */
+        iop_paranoia(iop_desc_get_next_desc(sw_desc));
 
         /* increment the pending count by the number of slots
          * memcpy operations have a 1:1 (slot:operation) relation