Hi Viresh, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Viresh-Kumar/opp-core-add-regula... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 1ae7efb388540adc1653a51a3bc3b2c9cef5ec1a If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; cppcheck warnings: (new ones prefixed by >>) ret = _set_required_opps(dev, opp_table, NULL); ^ drivers/opp/core.c:830:8: note: ret is assigned ret = -EINVAL; ^ drivers/opp/core.c:833:7: note: ret is overwritten ret = _set_required_opps(dev, opp_table, NULL); ^ vim +/ret +833 drivers/opp/core.c 793 794 /** 795 * dev_pm_opp_set_rate() - Configure new OPP based on frequency 796 * @dev: device for which we do this operation 797 * @target_freq: frequency to achieve 798 * 799 * This configures the power-supplies to the levels specified by the OPP 800 * corresponding to the target_freq, and programs the clock to a value <= 801 * target_freq, as rounded by clk_round_rate(). Device wanting to run at fmax 802 * provided by the opp, should have already rounded to the target OPP's 803 * frequency. 804 */ 805 int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) 806 { 807 struct opp_table *opp_table; 808 unsigned long freq, old_freq, temp_freq; 809 struct dev_pm_opp *old_opp, *opp; 810 struct clk *clk; 811 int ret; 812 813 opp_table = _find_opp_table(dev); 814 if (IS_ERR(opp_table)) { 815 dev_err(dev, "%s: device opp doesn't exist\n", __func__); 816 return PTR_ERR(opp_table); 817 } 818 819 if (unlikely(!target_freq)) { 820 /* 821 * Some drivers need to support cases where some platforms may 822 * have OPP table for the device, while others don't and 823 * opp_set_rate() just needs to behave like clk_set_rate(). 824 */ 825 if (!_get_opp_count(opp_table)) 826 return 0; 827 828 if (!opp_table->required_opp_tables) { 829 dev_err(dev, "target frequency can't be 0\n"); 830 ret = -EINVAL; 831 } 832 834 goto put_opp_table; 835 } 836 837 clk = opp_table->clk; 838 if (IS_ERR(clk)) { 839 dev_err(dev, "%s: No clock available for the device\n", 840 __func__); 841 ret = PTR_ERR(clk); 842 goto put_opp_table; 843 } 844 845 freq = clk_round_rate(clk, target_freq); 846 if ((long)freq <= 0) 847 freq = target_freq; 848 849 old_freq = clk_get_rate(clk); 850 851 /* Return early if nothing to do */ 852 if (old_freq == freq) { 853 dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n", 854 __func__, freq); 855 ret = 0; 856 goto put_opp_table; 857 } 858 859 /* 860 * For IO devices which require an OPP on some platforms/SoCs 861 * while just needing to scale the clock on some others 862 * we look for empty OPP tables with just a clock handle and 863 * scale only the clk. This makes dev_pm_opp_set_rate() 864 * equivalent to a clk_set_rate() 865 */ 866 if (!_get_opp_count(opp_table)) { 867 ret = _generic_set_opp_clk_only(dev, clk, freq); 868 goto put_opp_table; 869 } 870 871 temp_freq = old_freq; 872 old_opp = _find_freq_ceil(opp_table, &temp_freq); 873 if (IS_ERR(old_opp)) { 874 dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n", 875 __func__, old_freq, PTR_ERR(old_opp)); 876 } 877 878 temp_freq = freq; 879 opp = _find_freq_ceil(opp_table, &temp_freq); 880 if (IS_ERR(opp)) { 881 ret = PTR_ERR(opp); 882 dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n", 883 __func__, freq, ret); 884 goto put_old_opp; 885 } 886 887 dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__, 888 old_freq, freq); 889 890 /* Scaling up? Configure required OPPs before frequency */ 891 if (freq >= old_freq) { 892 ret = _set_required_opps(dev, opp_table, opp); 893 if (ret) 894 goto put_opp; 895 } 896 897 if (opp_table->set_opp) { 898 ret = _set_opp_custom(opp_table, dev, old_freq, freq, 899 IS_ERR(old_opp) ? NULL : old_opp->supplies, 900 opp->supplies); 901 } else if (opp_table->regulators) { 902 ret = _generic_set_opp_regulator(opp_table, dev, old_freq, freq, 903 IS_ERR(old_opp) ? NULL : old_opp->supplies, 904 opp->supplies); 905 } else { 906 /* Only frequency scaling */ 907 ret = _generic_set_opp_clk_only(dev, clk, freq); 908 } 909 910 /* Scaling down? Configure required OPPs after frequency */ 911 if (!ret && freq < old_freq) { 912 ret = _set_required_opps(dev, opp_table, opp); 913 if (ret) 914 dev_err(dev, "Failed to set required opps: %d\n", ret); 915 } 916 917 put_opp: 918 dev_pm_opp_put(opp); 919 put_old_opp: 920 if (!IS_ERR(old_opp)) 921 dev_pm_opp_put(old_opp); 922 put_opp_table: 923 dev_pm_opp_put_opp_table(opp_table); 924 return ret; 925 } 926 EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate); 927 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org