# \[PATCH\] video/chips: constify fb\_fix\_screeninfo and fb\_var\_screeninfo structures

- Subsystems: FRAMEBUFFER LAYER, THE REST
- Maintainers: Helge Deller, Linus Torvalds
- List: linux-fbdev
- 2 messages, 2 authors
- Page: https://ratatoskr.run/linux-fbdev/2017/07/5038821/t

## \[PATCH\] video/chips: constify fb\_fix\_screeninfo and fb\_var\_screeninfo structures

- From: Gustavo A. R. Silva \<hidden\>
- Date: 2017-07-08 01:15:57 
- Message: https://ratatoskr.run/linux-fbdev/2017/07/5038821.md

```text
These structures are only used to copy into other structures,
so declare them as const.

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

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

@ok@
identifier r.i;
expression e;
position p;
@@
e = i@p

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

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

The semantic patch for fb_var_screeninfo is analogous.

Signed-off-by: Gustavo A. R. Silva <redacted>
---
 drivers/video/fbdev/chipsfb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/chipsfb.c b/drivers/video/fbdev/chipsfb.c
index 59abdc6..f103665 100644
--- a/drivers/video/fbdev/chipsfb.c
+++ b/drivers/video/fbdev/chipsfb.c
@@ -292,7 +292,7 @@ static void chips_hw_init(void)
 		write_fr(chips_init_fr[i].addr, chips_init_fr[i].data);
 }
 
-static struct fb_fix_screeninfo chipsfb_fix = {
+static const struct fb_fix_screeninfo chipsfb_fix = {
 	.id =		"C&T 65550",
 	.type =		FB_TYPE_PACKED_PIXELS,
 	.visual =	FB_VISUAL_PSEUDOCOLOR,
@@ -309,7 +309,7 @@ static struct fb_fix_screeninfo chipsfb_fix = {
 	.smem_len =	0x100000,	/* 1MB */
 };
 
-static struct fb_var_screeninfo chipsfb_var = {
+static const struct fb_var_screeninfo chipsfb_var = {
 	.xres = 800,
 	.yres = 600,
 	.xres_virtual = 800,
-- 
2.5.0

```

## Re: \[PATCH\] video/chips: constify fb\_fix\_screeninfo and fb\_var\_screeninfo structures

- From: Bartlomiej Zolnierkiewicz \<hidden\>
- Date: 2017-08-01 12:34:38 
- Message: https://ratatoskr.run/linux-fbdev/2017/08/5056555.md

```text
On Friday, July 07, 2017 08:15:52 PM Gustavo A. R. Silva wrote:
> These structures are only used to copy into other structures,
> so declare them as const.
> 
> This issue was detected using Coccinelle and the following semantic patch:
> 
> @r disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct fb_fix_screeninfo i@p = { ... };
> 
> @ok@
> identifier r.i;
> expression e;
> position p;
> @@
> e = i@p
> 
> @bad@
> position p != {r.p,ok.p};
> identifier r.i;
> struct fb_fix_screeninfo e;
> @@
> e@i@p
> 
> @depends on !bad disable optional_qualifier@
> identifier r.i;
> @@
> static
> +const
>  struct fb_fix_screeninfo i = { ... };
> 
> The semantic patch for fb_var_screeninfo is analogous.
> 
> Signed-off-by: Gustavo A. R. Silva <redacted>

Patch queued for 4.14, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

```