path: root/drivers/staging/media/sunxi/cedrus/cedrus.c
diff options
authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-12-07 08:03:16 -0500
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-12-07 08:39:52 -0500
commite4d7b113fdccde1acf8638c5879f2a450d492303 (patch)
tree799a8a456750099c1cbb08323688453e87e3f39f /drivers/staging/media/sunxi/cedrus/cedrus.c
parent9ed5d5fb8b432badc967decf97e4294cbb216eef (diff)
media: cedrus: don't initialize pointers with zero
A common mistake is to assume that initializing a var with: struct foo f = { 0 }; Would initialize a zeroed struct. Actually, what this does is to initialize the first element of the struct to zero. According to C99 Standard "If there are fewer initializers in a brace-enclosed list than there are elements or members of an aggregate, or fewer characters in a string literal used to initialize an array of known size than there are elements in the array, the remainder of the aggregate shall be initialized implicitly the same as objects that have static storage duration." So, in practice, it could zero the entire struct, but, if the first element is not an integer, it will produce warnings: drivers/staging/media/sunxi/cedrus/cedrus.c:drivers/staging/media/sunxi/cedrus/cedrus.c:78:49: warning: Using plain integer as NULL pointer drivers/staging/media/sunxi/cedrus/cedrus_dec.c:drivers/staging/media/sunxi/cedrus/cedrus_dec.c:29:35: warning: Using plain integer as NULL pointer As the right initialization would be, instead: struct foo f = { NULL }; Another way to initialize it with gcc is to use: struct foo f = {}; That seems to be a gcc extension, but clang also does the right thing, and that's a clean way for doing it. Anyway, I decided to check upstream what's the most commonly pattern. The "= {}" pattern has about 2000 entries: $ git grep -E "=\s*\{\s*\}"|wc -l 1951 The standard-C compliant pattern has about 2500 entries: $ git grep -E "=\s*\{\s*NULL\s*\}"|wc -l 137 $ git grep -E "=\s*\{\s*0\s*\}"|wc -l 2323 Meaning that developers have split options on that. So, let's opt to the simpler form. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/staging/media/sunxi/cedrus/cedrus.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
index 4711df7ee5a3..ff11cbeba205 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
@@ -76,7 +76,7 @@ static int cedrus_init_ctrls(struct cedrus_dev *dev, struct cedrus_ctx *ctx)
return -ENOMEM;
for (i = 0; i < CEDRUS_CONTROLS_COUNT; i++) {
- struct v4l2_ctrl_config cfg = { 0 };
+ struct v4l2_ctrl_config cfg = {};
cfg.elem_size = cedrus_controls[i].elem_size;
cfg.id = cedrus_controls[i].id;

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