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-rw-r--r--arch/arm/common/dmabounce.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index 5797b1b100a..39dd33ff6f3 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -302,12 +302,24 @@ 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);
}