[PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[Krzysztof Kozlowski]

Statically allocated array of pointed to hwmon_channel_info can be made
const for safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

---

This depends on hwmon core patch:
https://lore.kernel.org/all/20230406203103.3011503-2-krzysztof.kozlowski@linaro.org/

Therefore I propose this should also go via hwmon tree.

Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
---
 drivers/media/i2c/video-i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
index dddf9827b314..abd472dcd497 100644
--- a/drivers/media/i2c/video-i2c.c
+++ b/drivers/media/i2c/video-i2c.c
@@ -274,7 +274,7 @@ static const struct hwmon_channel_info amg88xx_temp = {
 	.config = amg88xx_temp_config,
 };
 
-static const struct hwmon_channel_info *amg88xx_info[] = {
+static const struct hwmon_channel_info * const amg88xx_info[] = {
 	&amg88xx_temp,
 	NULL
 };
-- 
2.34.1

Re: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[kernel test robot]

Hi Krzysztof,

kernel test robot noticed the following build warnings:

[auto build test WARNING on media-tree/master]
[also build test WARNING on linus/master v6.3-rc5 next-20230406]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Krzysztof-Kozlowski/media-i2c-video-constify-pointers-to-hwmon_channel_info/20230407-230721
base:   git://linuxtv.org/media_tree.git master
patch link:    https://lore.kernel.org/r/20230407150015.79715-1-krzysztof.kozlowski%40linaro.org
patch subject: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230408/202304080056.8aAD0WhO-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/a9135e120b356553564ba1046e7752e4f9008666
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Krzysztof-Kozlowski/media-i2c-video-constify-pointers-to-hwmon_channel_info/20230407-230721
        git checkout a9135e120b356553564ba1046e7752e4f9008666
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/media/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304080056.8aAD0WhO-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/media/i2c/video-i2c.c:328:17: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     328 |         .info = amg88xx_info,
         |                 ^~~~~~~~~~~~


vim +/const +328 drivers/media/i2c/video-i2c.c

acbea6798955e9 Matt Ranostay 2018-06-28  325  
acbea6798955e9 Matt Ranostay 2018-06-28  326  static const struct hwmon_chip_info amg88xx_chip_info = {
acbea6798955e9 Matt Ranostay 2018-06-28  327  	.ops = &amg88xx_hwmon_ops,
acbea6798955e9 Matt Ranostay 2018-06-28 @328  	.info = amg88xx_info,
acbea6798955e9 Matt Ranostay 2018-06-28  329  };
acbea6798955e9 Matt Ranostay 2018-06-28  330  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[Sakari Ailus]

Hi Krzysztof,

On Fri, Apr 07, 2023 at 05:00:15PM +0200, Krzysztof Kozlowski wrote:
> Statically allocated array of pointed to hwmon_channel_info can be made
> const for safety.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> ---
> 
> This depends on hwmon core patch:
> https://lore.kernel.org/all/20230406203103.3011503-2-krzysztof.kozlowski@linaro.org/
> 
> Therefore I propose this should also go via hwmon tree.

Works for me. Please add:

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Thanks!

-- 
Kind regards,

Sakari Ailus

Re: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[Guenter Roeck]

On Fri, Apr 07, 2023 at 08:16:30PM +0300, Sakari Ailus wrote:
> Hi Krzysztof,
> 
> On Fri, Apr 07, 2023 at 05:00:15PM +0200, Krzysztof Kozlowski wrote:
> > Statically allocated array of pointed to hwmon_channel_info can be made
> > const for safety.
> > 
> > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > 
> > ---
> > 
> > This depends on hwmon core patch:
> > https://lore.kernel.org/all/20230406203103.3011503-2-krzysztof.kozlowski@linaro.org/
> > 
> > Therefore I propose this should also go via hwmon tree.
> 
> Works for me. Please add:
> 

But not for me. Krzysztof jumped the gun here a bit.
I do not feel comfortable applying patches for 10+ subsystem
branches through hwmon. This is asking for trouble.

I created a stable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-const

which everyone may use to merge the pre-requisite patch, or wait until
after the next merge window. 

Guenter

Re: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[Guenter Roeck]

On 4/7/23 08:00, Krzysztof Kozlowski wrote:
> Statically allocated array of pointed to hwmon_channel_info can be made
> const for safety.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> ---
> 
> This depends on hwmon core patch:
> https://lore.kernel.org/all/20230406203103.3011503-2-krzysztof.kozlowski@linaro.org/
> 
> Therefore I propose this should also go via hwmon tree.
> 

I am not going to apply patches for 10+ subsystems through the hwmon tree.
This can only result in chaos. The dependent patch is available at

git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-const

or wait until after the next commit window to apply this patch.

Thanks,
Guenter

> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: linux-hwmon@vger.kernel.org
> ---
>   drivers/media/i2c/video-i2c.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index dddf9827b314..abd472dcd497 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -274,7 +274,7 @@ static const struct hwmon_channel_info amg88xx_temp = {
>   	.config = amg88xx_temp_config,
>   };
>   
> -static const struct hwmon_channel_info *amg88xx_info[] = {
> +static const struct hwmon_channel_info * const amg88xx_info[] = {
>   	&amg88xx_temp,
>   	NULL
>   };

Re: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[kernel test robot]

Hi Krzysztof,

kernel test robot noticed the following build warnings:

[auto build test WARNING on media-tree/master]
[also build test WARNING on linus/master v6.3-rc5 next-20230406]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Krzysztof-Kozlowski/media-i2c-video-constify-pointers-to-hwmon_channel_info/20230407-230721
base:   git://linuxtv.org/media_tree.git master
patch link:    https://lore.kernel.org/r/20230407150015.79715-1-krzysztof.kozlowski%40linaro.org
patch subject: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info
config: s390-randconfig-s051-20230409 (https://download.01.org/0day-ci/archive/20230409/202304092352.T3BmNdHl-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 12.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://github.com/intel-lab-lkp/linux/commit/a9135e120b356553564ba1046e7752e4f9008666
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Krzysztof-Kozlowski/media-i2c-video-constify-pointers-to-hwmon_channel_info/20230407-230721
        git checkout a9135e120b356553564ba1046e7752e4f9008666
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=s390 SHELL=/bin/bash drivers/media/i2c/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304092352.T3BmNdHl-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/media/i2c/video-i2c.c:328:17: sparse: sparse: incorrect type in initializer (different modifiers) @@     expected struct hwmon_channel_info const **info @@     got struct hwmon_channel_info const *const * @@
   drivers/media/i2c/video-i2c.c:328:17: sparse:     expected struct hwmon_channel_info const **info
   drivers/media/i2c/video-i2c.c:328:17: sparse:     got struct hwmon_channel_info const *const *

vim +328 drivers/media/i2c/video-i2c.c

acbea6798955e9 Matt Ranostay 2018-06-28  325  
acbea6798955e9 Matt Ranostay 2018-06-28  326  static const struct hwmon_chip_info amg88xx_chip_info = {
acbea6798955e9 Matt Ranostay 2018-06-28  327  	.ops = &amg88xx_hwmon_ops,
acbea6798955e9 Matt Ranostay 2018-06-28 @328  	.info = amg88xx_info,
acbea6798955e9 Matt Ranostay 2018-06-28  329  };
acbea6798955e9 Matt Ranostay 2018-06-28  330  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH] media: i2c: video: constify pointers to hwmon_channel_info

[Matt Ranostay]

On Fri, Apr 7, 2023 at 8:00 AM Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> Statically allocated array of pointed to hwmon_channel_info can be made
> const for safety.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>

>
> ---
>
> This depends on hwmon core patch:
> https://lore.kernel.org/all/20230406203103.3011503-2-krzysztof.kozlowski@linaro.org/
>
> Therefore I propose this should also go via hwmon tree.
>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: linux-hwmon@vger.kernel.org
> ---
>  drivers/media/i2c/video-i2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index dddf9827b314..abd472dcd497 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -274,7 +274,7 @@ static const struct hwmon_channel_info amg88xx_temp = {
>         .config = amg88xx_temp_config,
>  };
>
> -static const struct hwmon_channel_info *amg88xx_info[] = {
> +static const struct hwmon_channel_info * const amg88xx_info[] = {
>         &amg88xx_temp,
>         NULL
>  };
> --
> 2.34.1
>