1 files changed, 16 insertions, 2 deletions

diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index 5797b1b100a1..9d63a01214eb 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -30,6 +30,8 @@
 #include <linux/dmapool.h>
 #include <linux/list.h>
 
+#include <asm/cacheflush.h>
+
 #undef DEBUG
 
 #undef STATS
@@ -302,12 +304,24 @@ unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 
                 DO_STATS ( device_info->bounce_count++ );
 
-                if ((dir == DMA_FROM_DEVICE) ||
-                    (dir == DMA_BIDIRECTIONAL)) {
+                if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
+                        unsigned long ptr;
+
                         dev_dbg(dev,
                                 "%s: copy back safe %p to unsafe %p size %d\n",
                                 __func__, buf->safe, buf->ptr, size);
                         memcpy(buf->ptr, buf->safe, size);
+
+                        /*
+                         * DMA buffers must have the same cache properties
+                         * as if they were really used for DMA - which means
+                         * data must be written back to RAM.  Note that
+                         * we don't use dmac_flush_range() here for the
+                         * bidirectional case because we know the cache
+                         * lines will be coherent with the data written.
+                         */
+                        ptr = (unsigned long)buf->ptr;
+                        dmac_clean_range(ptr, ptr + size);
                 }
                 free_safe_buffer(device_info, buf);
         }