[media] vb2: don't return NULL for alloc and get_userptr ops

Always return an ERR_PTR() instead of NULL.

This makes the behavior of alloc, get_userptr and attach_dmabuf the
same.

Update the documentation in videobuf2-core.h as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a4a9a55a0c42..b6546db670ca 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -33,7 +33,7 @@ struct vb2_threadio_data;
 /**
  * struct vb2_mem_ops - memory handling/memory allocator operations
  * @alloc:      allocate video memory and, optionally, allocator private data,
- *              return NULL on failure or a pointer to allocator private,
+ *              return ERR_PTR() on failure or a pointer to allocator private,
  *              per-buffer data on success; the returned private structure
  *              will then be passed as buf_priv argument to other ops in this
  *              structure. Additional gfp_flags to use when allocating the
@@ -50,14 +50,14 @@ struct vb2_threadio_data;
  *               USERPTR memory types; vaddr is the address passed to the
  *               videobuf layer when queuing a video buffer of USERPTR type;
  *               should return an allocator private per-buffer structure
- *               associated with the buffer on success, NULL on failure;
+ *               associated with the buffer on success, ERR_PTR() on failure;
  *               the returned private structure will then be passed as buf_priv
  *               argument to other ops in this structure.
  * @put_userptr: inform the allocator that a USERPTR buffer will no longer
  *               be used.
  * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
  *                 used for DMABUF memory types; dev is the alloc device
- *                 dbuf is the shared dma_buf; returns NULL on failure;
+ *                 dbuf is the shared dma_buf; returns ERR_PTR() on failure;
  *                 allocator private per-buffer structure on success;
  *                 this needs to be used for further accesses to the buffer.
  * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF