[PATCH] mtk-mdp: constify vb2_ops structure

From: Gustavo A. R. Silva
Date: Thu Jul 06 2017 - 16:46:46 EST


Check for vb2_ops structures that are only stored in the ops field of a
vb2_queue structure. That field is declared const, so vb2_ops structures
that have this property can be declared as const also.

This issue was detected using Coccinelle and the following semantic patch:

@r disable optional_qualifier@
identifier i;
position p;
@@
static struct vb2_ops i@p = { ... };

@ok@
identifier r.i;
struct vb2_queue e;
position p;
@@
e.ops = &i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
struct vb2_ops e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct vb2_ops i = { ... };

Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c b/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
index 13afe48..3038d62 100644
--- a/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
+++ b/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
@@ -621,7 +621,7 @@ static void mtk_mdp_m2m_buf_queue(struct vb2_buffer *vb)
v4l2_m2m_buf_queue(ctx->m2m_ctx, to_vb2_v4l2_buffer(vb));
}

-static struct vb2_ops mtk_mdp_m2m_qops = {
+static const struct vb2_ops mtk_mdp_m2m_qops = {
.queue_setup = mtk_mdp_m2m_queue_setup,
.buf_prepare = mtk_mdp_m2m_buf_prepare,
.buf_queue = mtk_mdp_m2m_buf_queue,
--
2.5.0