[PATCH 2/4] dma-buf: give examples of error codes to use

[Christian König]

The dma_fence_set_error() function allows to set an error code on a
dma_fence object before it is signaled.

Document some of the potential error codes drivers should use and
especially what they mean.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 include/linux/dma-fence.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index e06bad467f55..e7ad819962e3 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -574,6 +574,12 @@ int dma_fence_get_status(struct dma_fence *fence);
  * rather than success. This must be set before signaling (so that the value
  * is visible before any waiters on the signal callback are woken). This
  * helper exists to help catching erroneous setting of #dma_fence.error.
+ *
+ * Examples of error codes which drivers should use:
+ *
+ * * %-ENODATA	 This operation produced no data, no other operation affected.
+ * * %-ECANCELED All operations from the same context have been canceled.
+ * * %-ETIME	 Operation caused a timeout and potentially device reset.
  */
 static inline void dma_fence_set_error(struct dma_fence *fence,
 				       int error)
-- 
2.34.1