drm: Take ownership of the dmabuf->obj when exporting
Currently the reference for the dmabuf->obj is incremented for the
dmabuf in drm_gem_prime_handle_to_fd() (at the high level userspace
interface), but is released in drm_gem_dmabuf_release() (the lowlevel
handler). Improve the symmetry of the dmabuf->obj ownership by acquiring
the reference in drm_gem_dmabuf_export(). This makes it easier to use
the prime functions directly.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Update kerneldoc.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161207214527.22533-1-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index b22a94d..8d77b24 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -290,7 +290,8 @@
*
* This wraps dma_buf_export() for use by generic GEM drivers that are using
* drm_gem_dmabuf_release(). In addition to calling dma_buf_export(), we take
- * a reference to the drm_device which is released by drm_gem_dmabuf_release().
+ * a reference to the &drm_device and the exported &drm_gem_object (stored in
+ * exp_info->priv) which is released by drm_gem_dmabuf_release().
*
* Returns the new dmabuf.
*/
@@ -300,8 +301,11 @@
struct dma_buf *dma_buf;
dma_buf = dma_buf_export(exp_info);
- if (!IS_ERR(dma_buf))
- drm_dev_ref(dev);
+ if (IS_ERR(dma_buf))
+ return dma_buf;
+
+ drm_dev_ref(dev);
+ drm_gem_object_reference(exp_info->priv);
return dma_buf;
}
@@ -472,8 +476,6 @@
*/
obj->dma_buf = dmabuf;
get_dma_buf(obj->dma_buf);
- /* Grab a new ref since the callers is now used by the dma-buf */
- drm_gem_object_reference(obj);
return dmabuf;
}
diff --git a/drivers/gpu/drm/vgem/vgem_fence.c b/drivers/gpu/drm/vgem/vgem_fence.c
index 9cb00a5..da25dfe 100644
--- a/drivers/gpu/drm/vgem/vgem_fence.c
+++ b/drivers/gpu/drm/vgem/vgem_fence.c
@@ -126,7 +126,6 @@
return PTR_ERR(dmabuf);
obj->dma_buf = dmabuf;
- drm_gem_object_reference(obj);
return 0;
}