Re: [PATCH v8 3/3] media: i2c: Introduce a driver for the Techwell TW9900 decoder

[Dan Carpenter]

Hi Mehdi,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mehdi-Djait/dt-bindings-vendor-prefixes-Add-techwell-vendor-prefix/20231109-042139
base:   git://linuxtv.org/media_tree.git master
patch link:    https://lore.kernel.org/r/93354996c95926970684498f08061b60a52bb84c.1699449537.git.mehdi.djait%40bootlin.com
patch subject: [PATCH v8 3/3] media: i2c: Introduce a driver for the Techwell TW9900 decoder
config: i386-randconfig-141-20231111 (https://download.01.org/0day-ci/archive/20231111/202311110759.PJpNGc2N-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20231111/202311110759.PJpNGc2N-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
| Closes: https://lore.kernel.org/r/202311110759.PJpNGc2N-lkp@xxxxxxxxx/

smatch warnings:
drivers/media/i2c/tw9900.c:398 tw9900_s_std() error: uninitialized symbol 'mode'.

vim +/mode +398 drivers/media/i2c/tw9900.c

4fa88742527a9a Mehdi Djait 2023-11-08  384  static int tw9900_s_std(struct v4l2_subdev *sd, v4l2_std_id std)
4fa88742527a9a Mehdi Djait 2023-11-08  385  {
4fa88742527a9a Mehdi Djait 2023-11-08  386  	struct tw9900 *tw9900 = to_tw9900(sd);
4fa88742527a9a Mehdi Djait 2023-11-08  387  	const struct tw9900_mode *mode;

This should be "const struct tw9900_mode *mode = NULL;"

4fa88742527a9a Mehdi Djait 2023-11-08  388  	int i, ret = 0;
4fa88742527a9a Mehdi Djait 2023-11-08  389  
4fa88742527a9a Mehdi Djait 2023-11-08  390  	if (!(std & (V4L2_STD_NTSC | V4L2_STD_PAL)))
4fa88742527a9a Mehdi Djait 2023-11-08  391  		return -EINVAL;
4fa88742527a9a Mehdi Djait 2023-11-08  392  
4fa88742527a9a Mehdi Djait 2023-11-08  393  	mutex_lock(&tw9900->mutex);
4fa88742527a9a Mehdi Djait 2023-11-08  394  
4fa88742527a9a Mehdi Djait 2023-11-08  395  	for (i = 0; i < ARRAY_SIZE(supported_modes); i++)
4fa88742527a9a Mehdi Djait 2023-11-08  396  		if (supported_modes[i].std & std)
4fa88742527a9a Mehdi Djait 2023-11-08  397  			mode = &supported_modes[i];
4fa88742527a9a Mehdi Djait 2023-11-08 @398  	if (!mode) {
                                                     ^^^^
Either valid or uninitialized.

4fa88742527a9a Mehdi Djait 2023-11-08  399  		ret = -EINVAL;
4fa88742527a9a Mehdi Djait 2023-11-08  400  		goto out_unlock;
4fa88742527a9a Mehdi Djait 2023-11-08  401  	}
4fa88742527a9a Mehdi Djait 2023-11-08  402  
4fa88742527a9a Mehdi Djait 2023-11-08  403  	tw9900->cur_mode = mode;
4fa88742527a9a Mehdi Djait 2023-11-08  404  
4fa88742527a9a Mehdi Djait 2023-11-08  405  out_unlock:
4fa88742527a9a Mehdi Djait 2023-11-08  406  	mutex_unlock(&tw9900->mutex);
4fa88742527a9a Mehdi Djait 2023-11-08  407  
4fa88742527a9a Mehdi Djait 2023-11-08  408  	return ret;
4fa88742527a9a Mehdi Djait 2023-11-08  409  }

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