Re: [PATCH 6/6] [media] media: imx: capture: constify vb2_ops structures

From: Steve Longerbeam
Date: Mon Aug 14 2017 - 19:14:57 EST


Thanks,

Reviewed-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>

Steve

On 08/05/2017 03:47 AM, Julia Lawall wrote:
These vb2_ops structures are only stored in the ops field of a
vb2_queue structure, which is declared as const. Thus the vb2_ops
structures themselves can be const.

Done with the help of Coccinelle.

// <smpl>
@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 = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

---
drivers/staging/media/imx/imx-media-capture.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-capture.c b/drivers/staging/media/imx/imx-media-capture.c
index ddab4c2..ea145ba 100644
--- a/drivers/staging/media/imx/imx-media-capture.c
+++ b/drivers/staging/media/imx/imx-media-capture.c
@@ -62,7 +62,7 @@ struct capture_priv {
/* In bytes, per queue */
#define VID_MEM_LIMIT SZ_64M
-static struct vb2_ops capture_qops;
+static const struct vb2_ops capture_qops;
/*
* Video ioctls follow
@@ -503,7 +503,7 @@ static void capture_stop_streaming(struct vb2_queue *vq)
spin_unlock_irqrestore(&priv->q_lock, flags);
}
-static struct vb2_ops capture_qops = {
+static const struct vb2_ops capture_qops = {
.queue_setup = capture_queue_setup,
.buf_init = capture_buf_init,
.buf_prepare = capture_buf_prepare,