[PATCH] coresight: Add support of setting trace id

[kernel test robot]

Hi Mao,

kernel test robot noticed the following build warnings:

[auto build test WARNING on atorgue-stm32/stm32-next]
[also build test WARNING on soc/for-next linus/master v6.3-rc6 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/Mao-Jinlong/coresight-Add-support-of-setting-trace-id/20230410-214246
base:   https://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32.git stm32-next
patch link:    https://lore.kernel.org/r/20230410133930.30519-1-quic_jinlmao%40quicinc.com
patch subject: [PATCH] coresight: Add support of setting trace id
config: arm-randconfig-r024-20230410 (https://download.01.org/0day-ci/archive/20230411/202304111249.6nPH3yAY-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 2c57868e2e877f73c339796c3374ae660bb77f0d)
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
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/intel-lab-lkp/linux/commit/f92c27be62a6b3cef125e80682d265773e65cd13
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Mao-Jinlong/coresight-Add-support-of-setting-trace-id/20230410-214246
        git checkout f92c27be62a6b3cef125e80682d265773e65cd13
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/hwtracing/coresight/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304111249.6nPH3yAY-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/hwtracing/coresight/coresight-tpda.c:36:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
                   if (traceid < 0)
                       ^~~~~~~~~~~
   drivers/hwtracing/coresight/coresight-tpda.c:43:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/hwtracing/coresight/coresight-tpda.c:36:3: note: remove the 'if' if its condition is always true
                   if (traceid < 0)
                   ^~~~~~~~~~~~~~~~
   drivers/hwtracing/coresight/coresight-tpda.c:26:18: note: initialize the variable 'ret' to silence this warning
           int traceid, ret;
                           ^
                            = 0
   1 warning generated.


vim +36 drivers/hwtracing/coresight/coresight-tpda.c

    23	
    24	static int tpda_configure_trace_id(struct tpda_drvdata *drvdata)
    25	{
    26		int traceid, ret;
    27		/*
    28		 * TPDA must has a unique atid. This atid can uniquely
    29		 * identify the TPDM trace source connected to the TPDA.
    30		 * The TPDMs which are connected to same TPDA share the
    31		 * same trace-id. When TPDA does packetization, different
    32		 * port will have unique channel number for decoding.
    33		 */
    34		if (!drvdata->traceid) {
    35			traceid = coresight_trace_id_get_system_id();
  > 36			if (traceid < 0)
    37				return traceid;
    38	
    39			drvdata->traceid = traceid;
    40		} else
    41			ret = coresight_trace_id_set_system_id(drvdata->traceid);
    42	
    43		return ret;
    44	}
    45	

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