Re: [PATCH v2 23/39] drm/bridge: nxp-ptn3460: switch to ->edid_read callback

Re: [PATCH v2 23/39] drm/bridge: nxp-ptn3460: switch to ->edid_read callback

[kernel test robot]

Hi Jani,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on drm/drm-next drm-exynos/exynos-drm-next drm-intel/for-linux-next-fixes drm-tip/drm-tip linus/master v6.7-rc8 next-20240103]
[cannot apply to drm-intel/for-linux-next]
[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/Jani-Nikula/drm-bridge-add-edid_read-hook-and-drm_bridge_edid_read/20240103-181513
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/87fb7fd52d087dd9a15b7194f3915b6b1c4146d6.1704276309.git.jani.nikula%40intel.com
patch subject: [PATCH v2 23/39] drm/bridge: nxp-ptn3460: switch to ->edid_read callback
config: arm-randconfig-001-20240103 (https://download.01.org/0day-ci/archive/20240104/202401040455.PPhqJiVr-lkp@intel.com/config)
compiler: clang version 18.0.0git (https://github.com/llvm/llvm-project 7e186d366d6c7def0543acc255931f617e76dff0)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240104/202401040455.PPhqJiVr-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/202401040455.PPhqJiVr-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/nxp-ptn3460.c:170:6: warning: variable 'drm_edid' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
     170 |         if (!edid) {
         |             ^~~~~
   drivers/gpu/drm/bridge/nxp-ptn3460.c:189:9: note: uninitialized use occurs here
     189 |         return drm_edid;
         |                ^~~~~~~~
   drivers/gpu/drm/bridge/nxp-ptn3460.c:170:2: note: remove the 'if' if its condition is always false
     170 |         if (!edid) {
         |         ^~~~~~~~~~~~
     171 |                 DRM_ERROR("Failed to allocate EDID\n");
         |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     172 |                 goto out;
         |                 ~~~~~~~~~
     173 |         }
         |         ~
   drivers/gpu/drm/bridge/nxp-ptn3460.c:161:33: note: initialize the variable 'drm_edid' to silence this warning
     161 |         const struct drm_edid *drm_edid;
         |                                        ^
         |                                         = NULL
   1 warning generated.


vim +170 drivers/gpu/drm/bridge/nxp-ptn3460.c

a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  155  
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  156  
dd6c2ed9dace84 drivers/gpu/drm/bridge/nxp-ptn3460.c Jani Nikula  2024-01-03  157  static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge,
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  158  						struct drm_connector *connector)
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  159  {
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  160  	struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
dd6c2ed9dace84 drivers/gpu/drm/bridge/nxp-ptn3460.c Jani Nikula  2024-01-03  161  	const struct drm_edid *drm_edid;
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  162  	bool power_off;
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  163  	u8 *edid;
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  164  	int ret;
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  165  
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  166  	power_off = !ptn_bridge->enabled;
94d50d57c4403a drivers/gpu/drm/bridge/ptn3460.c     Ajay Kumar   2015-01-20  167  	ptn3460_pre_enable(&ptn_bridge->bridge);
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  168  
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  169  	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24 @170  	if (!edid) {
94d50d57c4403a drivers/gpu/drm/bridge/ptn3460.c     Ajay Kumar   2015-01-20  171  		DRM_ERROR("Failed to allocate EDID\n");
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  172  		goto out;
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  173  	}
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  174  
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  175  	ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  176  				 EDID_LENGTH);
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  177  	if (ret) {
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  178  		kfree(edid);
dd6c2ed9dace84 drivers/gpu/drm/bridge/nxp-ptn3460.c Jani Nikula  2024-01-03  179  		drm_edid = NULL;
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  180  		goto out;
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  181  	}
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  182  
dd6c2ed9dace84 drivers/gpu/drm/bridge/nxp-ptn3460.c Jani Nikula  2024-01-03  183  	drm_edid = drm_edid_alloc(edid, EDID_LENGTH);
dd6c2ed9dace84 drivers/gpu/drm/bridge/nxp-ptn3460.c Jani Nikula  2024-01-03  184  
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  185  out:
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  186  	if (power_off)
94d50d57c4403a drivers/gpu/drm/bridge/ptn3460.c     Ajay Kumar   2015-01-20  187  		ptn3460_disable(&ptn_bridge->bridge);
a9fe713d7d45c6 drivers/gpu/drm/bridge/ptn3460.c     Sean Paul    2014-02-24  188  
dd6c2ed9dace84 drivers/gpu/drm/bridge/nxp-ptn3460.c Jani Nikula  2024-01-03  189  	return drm_edid;
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  190  }
4151c14cdda689 drivers/gpu/drm/bridge/nxp-ptn3460.c Sam Ravnborg 2020-07-27  191  

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

Re: [PATCH v2 23/39] drm/bridge: nxp-ptn3460: switch to ->edid_read callback

[Jani Nikula]

On Thu, 04 Jan 2024, kernel test robot <lkp@intel.com> wrote:
> Hi Jani,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on drm-misc/drm-misc-next]
> [also build test WARNING on drm/drm-next drm-exynos/exynos-drm-next drm-intel/for-linux-next-fixes drm-tip/drm-tip linus/master v6.7-rc8 next-20240103]
> [cannot apply to drm-intel/for-linux-next]
> [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/Jani-Nikula/drm-bridge-add-edid_read-hook-and-drm_bridge_edid_read/20240103-181513
> base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
> patch link:    https://lore.kernel.org/r/87fb7fd52d087dd9a15b7194f3915b6b1c4146d6.1704276309.git.jani.nikula%40intel.com
> patch subject: [PATCH v2 23/39] drm/bridge: nxp-ptn3460: switch to ->edid_read callback
> config: arm-randconfig-001-20240103 (https://download.01.org/0day-ci/archive/20240104/202401040455.PPhqJiVr-lkp@intel.com/config)
> compiler: clang version 18.0.0git (https://github.com/llvm/llvm-project 7e186d366d6c7def0543acc255931f617e76dff0)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240104/202401040455.PPhqJiVr-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/202401040455.PPhqJiVr-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
>>> drivers/gpu/drm/bridge/nxp-ptn3460.c:170:6: warning: variable 'drm_edid' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>      170 |         if (!edid) {
>          |             ^~~~~
>    drivers/gpu/drm/bridge/nxp-ptn3460.c:189:9: note: uninitialized use occurs here
>      189 |         return drm_edid;
>          |                ^~~~~~~~
>    drivers/gpu/drm/bridge/nxp-ptn3460.c:170:2: note: remove the 'if' if its condition is always false
>      170 |         if (!edid) {
>          |         ^~~~~~~~~~~~
>      171 |                 DRM_ERROR("Failed to allocate EDID\n");
>          |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>      172 |                 goto out;
>          |                 ~~~~~~~~~
>      173 |         }
>          |         ~
>    drivers/gpu/drm/bridge/nxp-ptn3460.c:161:33: note: initialize the variable 'drm_edid' to silence this warning
>      161 |         const struct drm_edid *drm_edid;
>          |                                        ^
>          |                                         = NULL
>    1 warning generated.

This is a valid report, fixed locally.

BR,
Jani.


-- 
Jani Nikula, Intel