[ammarfaizi2-block:google/android/kernel/common/android11-kiwi-5.4 754/9999] drivers/rtc/hctosys.c:24:5: warning: no previous prototype for function 'rtc_hctosys'

From: kernel test robot
Date: Sat Jan 08 2022 - 02:50:57 EST


Hi Steve,

FYI, the error/warning still remains.

tree: https://github.com/ammarfaizi2/linux-block google/android/kernel/common/android11-kiwi-5.4
head: 7d1d5848183bd1d9086d0572f9af431d3ded407f
commit: 5f378fd56aa3988be21e859254a2d72628d044c6 [754/9999] ANDROID: rtc: class: support hctosys from modular RTC drivers
config: x86_64-randconfig-a011-20220107 (https://download.01.org/0day-ci/archive/20220108/202201081509.7cqEIyBV-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f3a344d2125fa37e59bae1b0874442c650a19607)
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/ammarfaizi2/linux-block/commit/5f378fd56aa3988be21e859254a2d72628d044c6
git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
git fetch --no-tags ammarfaizi2-block google/android/kernel/common/android11-kiwi-5.4
git checkout 5f378fd56aa3988be21e859254a2d72628d044c6
# 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=x86_64 SHELL=/bin/bash drivers/rtc/

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

All warnings (new ones prefixed by >>):

>> drivers/rtc/hctosys.c:24:5: warning: no previous prototype for function 'rtc_hctosys' [-Wmissing-prototypes]
int rtc_hctosys(void)
^
drivers/rtc/hctosys.c:24:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int rtc_hctosys(void)
^
static
1 warning generated.


vim +/rtc_hctosys +24 drivers/rtc/hctosys.c

12
13 /* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
14 * whether it stores the most close value or the value with partial
15 * seconds truncated. However, it is important that we use it to store
16 * the truncated value. This is because otherwise it is necessary,
17 * in an rtc sync function, to read both xtime.tv_sec and
18 * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read
19 * of >32bits is not possible. So storing the most close value would
20 * slow down the sync API. So here we have the truncated value and
21 * the best guess is to add 0.5s.
22 */
23
> 24 int rtc_hctosys(void)
25 {
26 int err = -ENODEV;
27 struct rtc_time tm;
28 struct timespec64 tv64 = {
29 .tv_nsec = NSEC_PER_SEC >> 1,
30 };
31 struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
32
33 if (!rtc) {
34 pr_info("unable to open rtc device (%s)\n",
35 CONFIG_RTC_HCTOSYS_DEVICE);
36 goto err_open;
37 }
38
39 err = rtc_read_time(rtc, &tm);
40 if (err) {
41 dev_err(rtc->dev.parent,
42 "hctosys: unable to read the hardware clock\n");
43 goto err_read;
44 }
45
46 tv64.tv_sec = rtc_tm_to_time64(&tm);
47

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx