[PATCH] nouveau: hide gcc-4.9 -Wmaybe-uninitialized

From: Arnd Bergmann
Date: Mon Oct 24 2016 - 11:31:21 EST


gcc-4.9 notices that the validate_init() function returns unintialized
data when called with a zero 'nr_buffers' argument, when called with the
-Wmaybe-uninitialized flag:

drivers/gpu/drm/nouveau/nouveau_gem.c: In function âvalidate_init.isra.6â:
drivers/gpu/drm/nouveau/nouveau_gem.c:457:5: error: âretâ may be used uninitialized in this function [-Werror=maybe-uninitialized]

However, the only caller of this function always passes a nonzero
argument, and gcc-6 is clever enough to take this into account and
not warn about it any more.

Adding an explicit initialization to -EINVAL here is correct even if
the caller changed, and it avoids the warning on gcc-4.9 as well.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_gem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 0bd7164bc817..4f3c5f3eaa16 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -369,7 +369,7 @@ validate_init(struct nouveau_channel *chan, struct drm_file *file_priv,
{
struct nouveau_cli *cli = nouveau_cli(file_priv);
int trycnt = 0;
- int ret, i;
+ int ret = -EINVAL, i;
struct nouveau_bo *res_bo = NULL;
LIST_HEAD(gart_list);
LIST_HEAD(vram_list);
--
2.9.0