dma-buf: make map_atomic and map function pointers optional

So drivers don't need dummy functions just returning NULL.

Cc: Daniel Vetter <[email protected]>
Signed-off-by: Gerd Hoffmann <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Reviewed-by: Oleksandr Andrushchenko <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 085db2fee2d7..88917fa796e4 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -39,12 +39,12 @@ struct dma_buf_attachment;
 
 /**
  * struct dma_buf_ops - operations possible on struct dma_buf
- * @map_atomic: maps a page from the buffer into kernel address
+ * @map_atomic: [optional] maps a page from the buffer into kernel address
  *		space, users may not block until the subsequent unmap call.
  *		This callback must not sleep.
  * @unmap_atomic: [optional] unmaps a atomically mapped page from the buffer.
  *		  This Callback must not sleep.
- * @map: maps a page from the buffer into kernel address space.
+ * @map: [optional] maps a page from the buffer into kernel address space.
  * @unmap: [optional] unmaps a page from the buffer.
  * @vmap: [optional] creates a virtual mapping for the buffer into kernel
  *	  address space. Same restrictions as for vmap and friends apply.