[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>

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index f50ff6f33c6f74059a9d2391d8daf7d748fa6f95..71d8bd8dcc8121543aa0a2db28c0383032bfb9a2 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -198,6 +198,7 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
                q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
        void *mem_priv;
        int plane;
+       int ret = -ENOMEM;
 
        /*
         * Allocate memory for all planes in this buffer
@@ -209,8 +210,11 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
                mem_priv = call_ptr_memop(vb, alloc,
                                q->alloc_devs[plane] ? : q->dev,
                                q->dma_attrs, size, dma_dir, q->gfp_flags);
-               if (IS_ERR_OR_NULL(mem_priv))
+               if (IS_ERR(mem_priv)) {
+                       if (mem_priv)
+                               ret = PTR_ERR(mem_priv);
                        goto free;
+               }
 
                /* Associate allocator private data with this plane */
                vb->planes[plane].mem_priv = mem_priv;
@@ -224,7 +228,7 @@ free:
                vb->planes[plane - 1].mem_priv = NULL;
        }
 
-       return -ENOMEM;
+       return ret;
 }
 
 /**
@@ -1136,10 +1140,10 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
                                q->alloc_devs[plane] ? : q->dev,
                                planes[plane].m.userptr,
                                planes[plane].length, dma_dir);
-               if (IS_ERR_OR_NULL(mem_priv)) {
+               if (IS_ERR(mem_priv)) {
                        dprintk(1, "failed acquiring userspace "
                                                "memory for plane %d\n", plane);
-                       ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
+                       ret = PTR_ERR(mem_priv);
                        goto err;
                }
                vb->planes[plane].mem_priv = mem_priv;

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index bd82d709ee8299967632f677d59e6412a451badc..e0165c10b82f343d7d5c561a87fddac5847d3c18 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -104,11 +104,12 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
        int ret;
        int num_pages;
 
-       if (WARN_ON(dev == NULL))
-               return NULL;
+       if (WARN_ON(!dev))
+               return ERR_PTR(-EINVAL);
+
        buf = kzalloc(sizeof *buf, GFP_KERNEL);
        if (!buf)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        buf->vaddr = NULL;
        buf->dma_dir = dma_dir;
@@ -166,7 +167,7 @@ fail_pages_alloc:
        kfree(buf->pages);
 fail_pages_array_alloc:
        kfree(buf);
-       return NULL;
+       return ERR_PTR(-ENOMEM);
 }
 
 static void vb2_dma_sg_put(void *buf_priv)
@@ -226,7 +227,7 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
 
        buf = kzalloc(sizeof *buf, GFP_KERNEL);
        if (!buf)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        buf->vaddr = NULL;
        buf->dev = dev;
@@ -266,7 +267,7 @@ userptr_fail_sgtable:
        vb2_destroy_framevec(vec);
 userptr_fail_pfnvec:
        kfree(buf);
-       return NULL;
+       return ERR_PTR(-ENOMEM);
 }
 
 /*

diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index c2820a6e164dec114a6a062c071da7414428bf95..ab3227b75c8486d0471bd603140e8cca88ce81b4 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -41,7 +41,7 @@ static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs,
 
        buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
        if (!buf)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        buf->size = size;
        buf->vaddr = vmalloc_user(buf->size);
@@ -53,7 +53,7 @@ static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs,
        if (!buf->vaddr) {
                pr_debug("vmalloc of size %ld failed\n", buf->size);
                kfree(buf);
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
 
        atomic_inc(&buf->refcount);
@@ -77,17 +77,20 @@ static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr,
        struct vb2_vmalloc_buf *buf;
        struct frame_vector *vec;
        int n_pages, offset, i;
+       int ret = -ENOMEM;
 
        buf = kzalloc(sizeof(*buf), GFP_KERNEL);
        if (!buf)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        buf->dma_dir = dma_dir;
        offset = vaddr & ~PAGE_MASK;
        buf->size = size;
        vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
-       if (IS_ERR(vec))
+       if (IS_ERR(vec)) {
+               ret = PTR_ERR(vec);
                goto fail_pfnvec_create;
+       }
        buf->vec = vec;
        n_pages = frame_vector_count(vec);
        if (frame_vector_to_pages(vec) < 0) {
@@ -117,7 +120,7 @@ fail_map:
 fail_pfnvec_create:
        kfree(buf);
 
-       return NULL;
+       return ERR_PTR(ret);
 }
 
 static void vb2_vmalloc_put_userptr(void *buf_priv)

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a4a9a55a0c42cd19a14c5fa7e0b9e91e063051ec..b6546db670cae50d27c66bfda5f0ab0bedd28d40 100644 (file)
--- 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