[PATCH] media: usbtv: constify static structs

From: Rikard Falkeborn
Date: Sat Feb 06 2021 - 16:26:22 EST


Constify two static structs which are never modified to allow the
compiler to put them in read-only memory.

The only usage of norm_params is only read from it in
usbtv_configure_for_norm(). Making it const shrinks the resulting
ko-file with 300 bytes (tested with gcc 10).

The only usage of usbtv_ioctl_ops is to put its address to the ioctl_ops
field in the video_device struct. Making it const moves ~1kb to
read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx>
---
drivers/media/usb/usbtv/usbtv-video.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c
index 3b4a2e769230..a714ad77ca8e 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -47,7 +47,7 @@

#include "usbtv.h"

-static struct usbtv_norm_params norm_params[] = {
+static const struct usbtv_norm_params norm_params[] = {
{
.norm = V4L2_STD_525_60,
.cap_width = 720,
@@ -63,7 +63,7 @@ static struct usbtv_norm_params norm_params[] = {
static int usbtv_configure_for_norm(struct usbtv *usbtv, v4l2_std_id norm)
{
int i, ret = 0;
- struct usbtv_norm_params *params = NULL;
+ const struct usbtv_norm_params *params = NULL;

for (i = 0; i < ARRAY_SIZE(norm_params); i++) {
if (norm_params[i].norm & norm) {
@@ -685,7 +685,7 @@ static int usbtv_s_input(struct file *file, void *priv, unsigned int i)
return usbtv_select_input(usbtv, i);
}

-static struct v4l2_ioctl_ops usbtv_ioctl_ops = {
+static const struct v4l2_ioctl_ops usbtv_ioctl_ops = {
.vidioc_querycap = usbtv_querycap,
.vidioc_enum_input = usbtv_enum_input,
.vidioc_enum_fmt_vid_cap = usbtv_enum_fmt_vid_cap,
--
2.30.0