Hi Rob, I love your patch! Perhaps something to improve: [auto build test WARNING on drm-misc/drm-misc-next] [also build test WARNING on rafael-pm/linux-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes drm-tip/drm-tip linus/master v6.3-rc3 next-20230320] [cannot apply to chanwoo/devfreq-testing] [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/Rob-Clark/drm-msm-Pre-allocate-hw_fence/20230320-224826 base: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next patch link: https://lore.kernel.org/r/20230320144356.803762-19-robdclark%40gmail.com patch subject: [PATCH v2 18/23] PM / QoS: Decouple request alloc from dev_pm_qos_mtx config: arm-randconfig-r005-20230319 (https://download.01.org/0day-ci/archive/20230321/202303210444.Qtybv08z-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 67409911353323ca5edf2049ef0df54132fa1ca7) 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/2d7e4629d7265d7e77fc72d01e84d27d805b7485 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Rob-Clark/drm-msm-Pre-allocate-hw_fence/20230320-224826 git checkout 2d7e4629d7265d7e77fc72d01e84d27d805b7485 # 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/base/power/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Link: https://lore.kernel.org/oe-kbuild-all/202303210444.Qtybv08z-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> drivers/base/power/qos.c:947:8: warning: variable 'req' is uninitialized when used here [-Wuninitialized] if (!req) { ^~~ drivers/base/power/qos.c:938:33: note: initialize the variable 'req' to silence this warning struct dev_pm_qos_request *req; ^ = NULL 1 warning generated. vim +/req +947 drivers/base/power/qos.c 2d984ad132a87c Rafael J. Wysocki 2014-02-11 917 2d984ad132a87c Rafael J. Wysocki 2014-02-11 918 /** 2d984ad132a87c Rafael J. Wysocki 2014-02-11 919 * dev_pm_qos_update_user_latency_tolerance - Update user space latency tolerance. 2d984ad132a87c Rafael J. Wysocki 2014-02-11 920 * @dev: Device to update the user space latency tolerance for. 2d984ad132a87c Rafael J. Wysocki 2014-02-11 921 * @val: New user space latency tolerance for @dev (negative values disable). 2d984ad132a87c Rafael J. Wysocki 2014-02-11 922 */ 2d984ad132a87c Rafael J. Wysocki 2014-02-11 923 int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val) 2d984ad132a87c Rafael J. Wysocki 2014-02-11 924 { 2d7e4629d7265d Rob Clark 2023-03-20 925 struct dev_pm_qos_request *req = NULL; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 926 int ret; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 927 00dd582e52a535 Rob Clark 2023-03-20 928 ret = dev_pm_qos_constraints_ensure_allocated(dev); 00dd582e52a535 Rob Clark 2023-03-20 929 if (ret) 00dd582e52a535 Rob Clark 2023-03-20 930 return ret; 00dd582e52a535 Rob Clark 2023-03-20 931 2d7e4629d7265d Rob Clark 2023-03-20 932 if (!dev->power.qos->latency_tolerance_req) 2d7e4629d7265d Rob Clark 2023-03-20 933 req = kzalloc(sizeof(*req), GFP_KERNEL); 2d7e4629d7265d Rob Clark 2023-03-20 934 2d984ad132a87c Rafael J. Wysocki 2014-02-11 935 mutex_lock(&dev_pm_qos_mtx); 2d984ad132a87c Rafael J. Wysocki 2014-02-11 936 00dd582e52a535 Rob Clark 2023-03-20 937 if (!dev->power.qos->latency_tolerance_req) { 2d984ad132a87c Rafael J. Wysocki 2014-02-11 938 struct dev_pm_qos_request *req; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 939 2d984ad132a87c Rafael J. Wysocki 2014-02-11 940 if (val < 0) { 80a6f7c79b7822 Andrew Lutomirski 2016-11-29 941 if (val == PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT) 80a6f7c79b7822 Andrew Lutomirski 2016-11-29 942 ret = 0; 80a6f7c79b7822 Andrew Lutomirski 2016-11-29 943 else 2d984ad132a87c Rafael J. Wysocki 2014-02-11 944 ret = -EINVAL; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 945 goto out; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 946 } 2d984ad132a87c Rafael J. Wysocki 2014-02-11 @947 if (!req) { 2d984ad132a87c Rafael J. Wysocki 2014-02-11 948 ret = -ENOMEM; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 949 goto out; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 950 } 2d984ad132a87c Rafael J. Wysocki 2014-02-11 951 ret = __dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY_TOLERANCE, val); 2d984ad132a87c Rafael J. Wysocki 2014-02-11 952 if (ret < 0) { 2d984ad132a87c Rafael J. Wysocki 2014-02-11 953 kfree(req); 2d984ad132a87c Rafael J. Wysocki 2014-02-11 954 goto out; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 955 } 2d984ad132a87c Rafael J. Wysocki 2014-02-11 956 dev->power.qos->latency_tolerance_req = req; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 957 } else { 2d7e4629d7265d Rob Clark 2023-03-20 958 /* 2d7e4629d7265d Rob Clark 2023-03-20 959 * If we raced with another thread to allocate the request, 2d7e4629d7265d Rob Clark 2023-03-20 960 * simply free the redundant allocation and move on. 2d7e4629d7265d Rob Clark 2023-03-20 961 */ 2d7e4629d7265d Rob Clark 2023-03-20 962 if (req) 2d7e4629d7265d Rob Clark 2023-03-20 963 kfree(req); 2d7e4629d7265d Rob Clark 2023-03-20 964 2d984ad132a87c Rafael J. Wysocki 2014-02-11 965 if (val < 0) { 2d984ad132a87c Rafael J. Wysocki 2014-02-11 966 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY_TOLERANCE); 2d984ad132a87c Rafael J. Wysocki 2014-02-11 967 ret = 0; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 968 } else { 2d984ad132a87c Rafael J. Wysocki 2014-02-11 969 ret = __dev_pm_qos_update_request(dev->power.qos->latency_tolerance_req, val); 2d984ad132a87c Rafael J. Wysocki 2014-02-11 970 } 2d984ad132a87c Rafael J. Wysocki 2014-02-11 971 } 2d984ad132a87c Rafael J. Wysocki 2014-02-11 972 2d984ad132a87c Rafael J. Wysocki 2014-02-11 973 out: 2d984ad132a87c Rafael J. Wysocki 2014-02-11 974 mutex_unlock(&dev_pm_qos_mtx); 2d984ad132a87c Rafael J. Wysocki 2014-02-11 975 return ret; 2d984ad132a87c Rafael J. Wysocki 2014-02-11 976 } 034e7906211c18 Andrew Lutomirski 2016-11-29 977 EXPORT_SYMBOL_GPL(dev_pm_qos_update_user_latency_tolerance); 13b2c4a0c3b1cd Mika Westerberg 2015-07-27 978 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
