drm/atomic: Initialize variables in drm_atomic_helper_async_check() to make gcc happy

commit de2d8db395c32d121d02871819444b631f73e0b6 upstream.

drm_atomic_helper_async_check() declares the plane, old_plane_state and
new_plane_state variables to iterate over all planes of the atomic
state and make sure only one plane is enabled.

Unfortunately gcc is not smart enough to figure out that the check on
n_planes is enough to guarantee that plane, new_plane_state and
old_plane_state are initialized.

Explicitly initialize those variables to NULL to make gcc happy.

Fixes: fef9df8b5945 ("drm/atomic: initial support for asynchronous plane update")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180724133300.32023-1-boris.brezillon@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 33c582a82d8270f9fb51a35fe2dc4b3466ec5d32..bc8c1c7afb84ee940efb4c7d7de77931079ee325 100644 (file)
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1499,8 +1499,9 @@ int drm_atomic_helper_async_check(struct drm_device *dev,
 {
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
-       struct drm_plane *plane;
-       struct drm_plane_state *old_plane_state, *new_plane_state;
+       struct drm_plane *plane = NULL;
+       struct drm_plane_state *old_plane_state = NULL;
+       struct drm_plane_state *new_plane_state = NULL;
        const struct drm_plane_helper_funcs *funcs;
        int i, n_planes = 0;