Re: [PATCH v8 1/2] drivers: ddcci: upstream DDCCI driver

[kernel test robot <lkp@intel.com>]

Hi Yusuf,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on linux/master linus/master lee-backlight/for-backlight-next v5.17 next-20220318]
[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]

url:    https://github.com/0day-ci/linux/commits/Yusuf-Khan/drivers-ddcci-upstream-DDCCI-driver/20220321-111557
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git 37fd83916da2e4cae03d350015c82a67b1b334c4
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20220321/202203211954.b6DnJ7FO-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 85e9b2687a13d1908aa86d1b89c5ce398a06cd39)
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/0day-ci/linux/commit/42317fc284bbedc623892f2b20e404df80f8c393
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Yusuf-Khan/drivers-ddcci-upstream-DDCCI-driver/20220321-111557
        git checkout 42317fc284bbedc623892f2b20e404df80f8c393
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/char/ drivers/soc/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/char/ddcci.c:1157:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->module) || (strcmp(device->module, id->module) == 0))) {
                        ^~~~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:49: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                                            ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1157:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->module) || (strcmp(device->module, id->module) == 0))) {
                        ^~~~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:31: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                          ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1156:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->vendor) || (strcmp(device->vendor, id->vendor) == 0))
                        ^~~~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:49: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                                            ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1156:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->vendor) || (strcmp(device->vendor, id->vendor) == 0))
                        ^~~~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:31: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                          ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1155:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->model) || (strcmp(device->model, id->model) == 0))
                        ^~~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:49: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                                            ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1155:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->model) || (strcmp(device->model, id->model) == 0))
                        ^~~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:31: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                          ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1154:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->type) || (strcmp(device->type, id->type) == 0))
                        ^~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:49: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                                            ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1154:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                    && (IS_ANY_ID(id->type) || (strcmp(device->type, id->type) == 0))
                        ^~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:31: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                          ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1153:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                   if ((IS_ANY_ID(id->prot) || (strcmp(device->prot, id->prot) == 0))
                        ^~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:49: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                                            ~~~~~~ ^  ~~
   drivers/char/ddcci.c:1153:8: warning: result of comparison of constant -1 with expression of type 'const char' is always false [-Wtautological-constant-out-of-range-compare]
                   if ((IS_ANY_ID(id->prot) || (strcmp(device->prot, id->prot) == 0))
                        ^~~~~~~~~~~~~~~~~~~
   drivers/char/ddcci.c:1146:31: note: expanded from macro 'IS_ANY_ID'
   #define IS_ANY_ID(x) (((x)[0] == -1) && ((x)[7] == -1))
                          ~~~~~~ ^  ~~
>> drivers/char/ddcci.c:1206:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
           int ret = 0;
               ^
   11 warnings generated.


vim +/ret +1206 drivers/char/ddcci.c

  1201	
  1202	static void ddcci_device_remove(struct device *dev)
  1203	{
  1204		struct ddcci_device	*device = ddcci_verify_device(dev);
  1205		struct ddcci_driver	*driver;
> 1206		int ret = 0;
  1207	
  1208		if (!device)
  1209			return;
  1210		driver = to_ddcci_driver(dev->driver);
  1211	
  1212		if (driver->remove)
  1213			ret = driver->remove(device);
  1214	}
  1215	

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