[PATCH v2] drm/fb-helper: Do the 'max_conn_count' zero check

[Xiubo Li <Li.Xiubo@freescale.com>]

Since we cannot make sure the 'max_conn_count' will always be none
zero from the users, and then if max_conn_count equals to zero, the
kcalloc() will return ZERO_SIZE_PTR, which equals to ((void *)16).

So this patch fix this with just doing the 'max_conn_count' zero check
in the front of drm_fb_helper_init().

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
CC: Jani Nikula <jani.nikula@linux.intel.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 3d13ca6e2..a0d286c 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -514,6 +514,9 @@ int drm_fb_helper_init(struct drm_device *dev,
 	struct drm_crtc *crtc;
 	int i;
 
+	if (!max_conn_count)
+		return -EINVAL;
+
 	fb_helper->dev = dev;
 
 	INIT_LIST_HEAD(&fb_helper->kernel_fb_list);
-- 
1.8.4