[RFC 1/4] drm: allow to create blank writable blob properties

[Rahul Sharma]

There is no provision to create a blob property without
providing binary data. This data is needed to fill inside
the blob.

With subsequent patches, blob properties are modified to
receive well defined structures by the user application.
DRM creates a blank blob (initialized with all zeros) which
can be filled by user application through set_blob ioctl.

Signed-off-by: Rahul Sharma <rahul.sharma at samsung.com>
---
 drivers/gpu/drm/drm_crtc.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 35ea15d..9a2215c 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3190,7 +3190,7 @@ static struct drm_property_blob *drm_property_create_blob(struct drm_device *dev
 	struct drm_property_blob *blob;
 	int ret;
 
-	if (!length || !data)
+	if (!length)
 		return NULL;
 
 	blob = kzalloc(sizeof(struct drm_property_blob)+length, GFP_KERNEL);
@@ -3205,7 +3205,8 @@ static struct drm_property_blob *drm_property_create_blob(struct drm_device *dev
 
 	blob->length = length;
 
-	memcpy(blob->data, data, length);
+	if (data)
+		memcpy(blob->data, data, length);
 
 	list_add_tail(&blob->head, &dev->mode_config.property_blob_list);
 	return blob;
-- 
1.7.9.5