dma-buf: might_sleep() in dma_buf_unmap_attachment()

We never really clarified if unmap could be done in atomic context.
But since mapping might require sleeping, this implies mutex in use
to synchronize mapping/unmapping, so unmap could sleep as well.  Add
a might_sleep() to clarify this.

Signed-off-by: Rob Clark <rob@ti.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 460e22dee36d..a3f79c495a41 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -298,6 +298,8 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
                                 struct sg_table *sg_table,
                                 enum dma_data_direction direction)
 {
+        might_sleep();
+
         if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
                 return;