tree: https://android.googlesource.com/kernel/omap mirror-android-4.19-r head: 0b145f91d8fdbe39900356c8ad3ba4e41ce95fab commit: 0b145f91d8fdbe39900356c8ad3ba4e41ce95fab [1/1] ANDROID: rtc: class: support hctosys from modular RTC drivers config: arm-randconfig-r032-20210409 (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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 git remote add android-omap https://android.googlesource.com/kernel/omap git fetch --no-tags android-omap mirror-android-4.19-r git checkout 0b145f91d8fdbe39900356c8ad3ba4e41ce95fab # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): 27 | int rtc_hctosys(void) | ^~~~~~~~~~~ vim +/rtc_hctosys +27 drivers/rtc/hctosys.c 15 16 /* IMPORTANT: the RTC only stores whole seconds. It is arbitrary 17 * whether it stores the most close value or the value with partial 18 * seconds truncated. However, it is important that we use it to store 19 * the truncated value. This is because otherwise it is necessary, 20 * in an rtc sync function, to read both xtime.tv_sec and 21 * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read 22 * of >32bits is not possible. So storing the most close value would 23 * slow down the sync API. So here we have the truncated value and 24 * the best guess is to add 0.5s. 25 */ 26 28 { 29 int err = -ENODEV; 30 struct rtc_time tm; 31 struct timespec64 tv64 = { 32 .tv_nsec = NSEC_PER_SEC >> 1, 33 }; 34 struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE); 35 36 if (rtc == NULL) { 37 pr_info("unable to open rtc device (%s)\n", 38 CONFIG_RTC_HCTOSYS_DEVICE); 39 goto err_open; 40 } 41 42 err = rtc_read_time(rtc, &tm); 43 if (err) { 44 dev_err(rtc->dev.parent, 45 "hctosys: unable to read the hardware clock\n"); 46 goto err_read; 47 48 } 49 50 tv64.tv_sec = rtc_tm_to_time64(&tm); 51 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org