diff options
| -rw-r--r-- | arch/arm/common/dmabounce.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c index 5797b1b100a1..39dd33ff6f37 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); } |