* [linux-next:master 4727/8441] drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false
@ 2023-08-09 10:27 kernel test robot
2023-08-17 17:06 ` Lee Jones
0 siblings, 1 reply; 4+ messages in thread
From: kernel test robot @ 2023-08-09 10:27 UTC (permalink / raw)
To: Artur Weber
Cc: llvm, oe-kbuild-all, Linux Memory Management List, Lee Jones,
Daniel Thompson
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: 21ef7b1e17d039053edaeaf41142423810572741
commit: 5145531be5fbad0e914d1dc1cbd392d7b756abaa [4727/8441] backlight: lp855x: Catch errors when changing brightness
config: x86_64-buildonly-randconfig-r002-20230808 (https://download.01.org/0day-ci/archive/20230809/202308091728.NEJhgUPP-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce: (https://download.01.org/0day-ci/archive/20230809/202308091728.NEJhgUPP-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308091728.NEJhgUPP-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
else if (lp->mode == REGISTER_BASED)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:55:28: note: expanded from macro 'if'
#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:57:30: note: expanded from macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/video/backlight/lp855x_bl.c:256:9: note: uninitialized use occurs here
return ret;
^~~
drivers/video/backlight/lp855x_bl.c:252:7: note: remove the 'if' if its condition is always true
else if (lp->mode == REGISTER_BASED)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:55:23: note: expanded from macro 'if'
#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
^
drivers/video/backlight/lp855x_bl.c:244:9: note: initialize the variable 'ret' to silence this warning
int ret;
^
= 0
1 warning generated.
vim +252 drivers/video/backlight/lp855x_bl.c
8cc9764c9c7d01 Kim, Milo 2012-12-17 239
7be865ab8634d4 Kim, Milo 2012-03-23 240 static int lp855x_bl_update_status(struct backlight_device *bl)
7be865ab8634d4 Kim, Milo 2012-03-23 241 {
7be865ab8634d4 Kim, Milo 2012-03-23 242 struct lp855x *lp = bl_get_data(bl);
61c1c6147f69d8 Sean Paul 2015-05-11 243 int brightness = bl->props.brightness;
5145531be5fbad Artur Weber 2023-07-14 244 int ret;
7be865ab8634d4 Kim, Milo 2012-03-23 245
9f0a511f4a227c Shingo Nakao 2013-07-02 246 if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
61c1c6147f69d8 Sean Paul 2015-05-11 247 brightness = 0;
7be865ab8634d4 Kim, Milo 2012-03-23 248
61c1c6147f69d8 Sean Paul 2015-05-11 249 if (lp->mode == PWM_BASED)
5145531be5fbad Artur Weber 2023-07-14 250 ret = lp855x_pwm_ctrl(lp, brightness,
5145531be5fbad Artur Weber 2023-07-14 251 bl->props.max_brightness);
61c1c6147f69d8 Sean Paul 2015-05-11 @252 else if (lp->mode == REGISTER_BASED)
5145531be5fbad Artur Weber 2023-07-14 253 ret = lp855x_write_byte(lp, lp->cfg->reg_brightness,
5145531be5fbad Artur Weber 2023-07-14 254 (u8)brightness);
7be865ab8634d4 Kim, Milo 2012-03-23 255
5145531be5fbad Artur Weber 2023-07-14 256 return ret;
7be865ab8634d4 Kim, Milo 2012-03-23 257 }
7be865ab8634d4 Kim, Milo 2012-03-23 258
:::::: The code at line 252 was first introduced by commit
:::::: 61c1c6147f69d8dea31fd133d2ec0b1594c9a3eb backlight: lp855x: Don't clear level on suspend/blank
:::::: TO: Sean Paul <seanpaul@chromium.org>
:::::: CC: Lee Jones <lee.jones@linaro.org>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [linux-next:master 4727/8441] drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false
2023-08-09 10:27 [linux-next:master 4727/8441] drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false kernel test robot
@ 2023-08-17 17:06 ` Lee Jones
2023-08-17 17:08 ` Nathan Chancellor
0 siblings, 1 reply; 4+ messages in thread
From: Lee Jones @ 2023-08-17 17:06 UTC (permalink / raw)
To: kernel test robot
Cc: Artur Weber, llvm, oe-kbuild-all, Linux Memory Management List,
Daniel Thompson
Arthur,
Please submit a follow-up patch or I'll have to revert it.
Thanks.
On Wed, 09 Aug 2023, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head: 21ef7b1e17d039053edaeaf41142423810572741
> commit: 5145531be5fbad0e914d1dc1cbd392d7b756abaa [4727/8441] backlight: lp855x: Catch errors when changing brightness
> config: x86_64-buildonly-randconfig-r002-20230808 (https://download.01.org/0day-ci/archive/20230809/202308091728.NEJhgUPP-lkp@intel.com/config)
> compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
> reproduce: (https://download.01.org/0day-ci/archive/20230809/202308091728.NEJhgUPP-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202308091728.NEJhgUPP-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> >> drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
> else if (lp->mode == REGISTER_BASED)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler.h:55:28: note: expanded from macro 'if'
> #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler.h:57:30: note: expanded from macro '__trace_if_var'
> #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/video/backlight/lp855x_bl.c:256:9: note: uninitialized use occurs here
> return ret;
> ^~~
> drivers/video/backlight/lp855x_bl.c:252:7: note: remove the 'if' if its condition is always true
> else if (lp->mode == REGISTER_BASED)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler.h:55:23: note: expanded from macro 'if'
> #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
> ^
> drivers/video/backlight/lp855x_bl.c:244:9: note: initialize the variable 'ret' to silence this warning
> int ret;
> ^
> = 0
> 1 warning generated.
>
>
> vim +252 drivers/video/backlight/lp855x_bl.c
>
> 8cc9764c9c7d01 Kim, Milo 2012-12-17 239
> 7be865ab8634d4 Kim, Milo 2012-03-23 240 static int lp855x_bl_update_status(struct backlight_device *bl)
> 7be865ab8634d4 Kim, Milo 2012-03-23 241 {
> 7be865ab8634d4 Kim, Milo 2012-03-23 242 struct lp855x *lp = bl_get_data(bl);
> 61c1c6147f69d8 Sean Paul 2015-05-11 243 int brightness = bl->props.brightness;
> 5145531be5fbad Artur Weber 2023-07-14 244 int ret;
> 7be865ab8634d4 Kim, Milo 2012-03-23 245
> 9f0a511f4a227c Shingo Nakao 2013-07-02 246 if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
> 61c1c6147f69d8 Sean Paul 2015-05-11 247 brightness = 0;
> 7be865ab8634d4 Kim, Milo 2012-03-23 248
> 61c1c6147f69d8 Sean Paul 2015-05-11 249 if (lp->mode == PWM_BASED)
> 5145531be5fbad Artur Weber 2023-07-14 250 ret = lp855x_pwm_ctrl(lp, brightness,
> 5145531be5fbad Artur Weber 2023-07-14 251 bl->props.max_brightness);
> 61c1c6147f69d8 Sean Paul 2015-05-11 @252 else if (lp->mode == REGISTER_BASED)
> 5145531be5fbad Artur Weber 2023-07-14 253 ret = lp855x_write_byte(lp, lp->cfg->reg_brightness,
> 5145531be5fbad Artur Weber 2023-07-14 254 (u8)brightness);
> 7be865ab8634d4 Kim, Milo 2012-03-23 255
> 5145531be5fbad Artur Weber 2023-07-14 256 return ret;
> 7be865ab8634d4 Kim, Milo 2012-03-23 257 }
> 7be865ab8634d4 Kim, Milo 2012-03-23 258
>
> :::::: The code at line 252 was first introduced by commit
> :::::: 61c1c6147f69d8dea31fd133d2ec0b1594c9a3eb backlight: lp855x: Don't clear level on suspend/blank
>
> :::::: TO: Sean Paul <seanpaul@chromium.org>
> :::::: CC: Lee Jones <lee.jones@linaro.org>
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
--
Lee Jones [李琼斯]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [linux-next:master 4727/8441] drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false
2023-08-17 17:06 ` Lee Jones
@ 2023-08-17 17:08 ` Nathan Chancellor
2023-08-17 19:52 ` Lee Jones
0 siblings, 1 reply; 4+ messages in thread
From: Nathan Chancellor @ 2023-08-17 17:08 UTC (permalink / raw)
To: Lee Jones
Cc: kernel test robot, Artur Weber, llvm, oe-kbuild-all,
Linux Memory Management List, Daniel Thompson
On Thu, Aug 17, 2023 at 06:06:02PM +0100, Lee Jones wrote:
> Arthur,
>
> Please submit a follow-up patch or I'll have to revert it.
The follow up fix was sent a couple hours after this report:
https://lore.kernel.org/20230809114216.4078-1-aweber.kernel@gmail.com/
Cheers,
Nathan
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [linux-next:master 4727/8441] drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false
2023-08-17 17:08 ` Nathan Chancellor
@ 2023-08-17 19:52 ` Lee Jones
0 siblings, 0 replies; 4+ messages in thread
From: Lee Jones @ 2023-08-17 19:52 UTC (permalink / raw)
To: Nathan Chancellor
Cc: kernel test robot, Artur Weber, llvm, oe-kbuild-all,
Linux Memory Management List, Daniel Thompson
On Thu, 17 Aug 2023, Nathan Chancellor wrote:
> On Thu, Aug 17, 2023 at 06:06:02PM +0100, Lee Jones wrote:
> > Arthur,
> >
> > Please submit a follow-up patch or I'll have to revert it.
>
> The follow up fix was sent a couple hours after this report:
>
> https://lore.kernel.org/20230809114216.4078-1-aweber.kernel@gmail.com/
Super, thanks.
I had a simple grep for a follow-up, but must have missed it. I'll
probably get up to it (working reverse chronologically) tomorrow some
time.
--
Lee Jones [李琼斯]
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-08-09 10:27 [linux-next:master 4727/8441] drivers/video/backlight/lp855x_bl.c:252:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false kernel test robot
2023-08-17 17:06 ` Lee Jones
2023-08-17 17:08 ` Nathan Chancellor
2023-08-17 19:52 ` Lee Jones
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