1 files changed, 6 insertions, 3 deletions

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 4d9b4388918b..946f3219fd29 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -334,9 +334,6 @@ int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
 
         spin_unlock_irqrestore(&(tbl->it_lock), flags);
 
-        /* Make sure updates are seen by hardware */
-        mb();
-
         DBG("mapped %d elements:\n", outcount);
 
         /* For the sake of iommu_unmap_sg, we clear out the length in the
@@ -347,6 +344,10 @@ int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
                 outs->dma_address = DMA_ERROR_CODE;
                 outs->dma_length = 0;
         }
+
+        /* Make sure updates are seen by hardware */
+        mb();
+
         return outcount;
 
  failure:
@@ -358,6 +359,8 @@ int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
                         npages = (PAGE_ALIGN(s->dma_address + s->dma_length) - vaddr)
                                 >> PAGE_SHIFT;
                         __iommu_free(tbl, vaddr, npages);
+                        s->dma_address = DMA_ERROR_CODE;
+                        s->dma_length = 0;
                 }
         }
         spin_unlock_irqrestore(&(tbl->it_lock), flags);