diff options
Diffstat (limited to 'sys-utils/hwclock.c')
| -rw-r--r-- | sys-utils/hwclock.c | 56 |
1 files changed, 35 insertions, 21 deletions
diff --git a/sys-utils/hwclock.c b/sys-utils/hwclock.c index dc8f9574e..9a4a70629 100644 --- a/sys-utils/hwclock.c +++ b/sys-utils/hwclock.c @@ -981,12 +981,13 @@ static int set_system_clock_timezone(const bool universal, const bool testing) } /* - * Update the drift factor in <*adjtime_p> to reflect the fact that the - * Hardware Clock was calibrated to <nowtime> and before that was set to - * <hclocktime>. + * Refresh the last calibrated and last adjusted timestamps in <*adjtime_p> + * to facilitate future drift calculations based on this set point. * - * We record in the adjtime file the time at which we last calibrated the - * clock so we can compute the drift rate each time we calibrate. + * With the --update-drift option: + * Update the drift factor in <*adjtime_p> based on the fact that the + * Hardware Clock was just calibrated to <nowtime> and before that was + * set to the <hclocktime> time scale. * * EXCEPT: if <hclock_valid> is false, assume Hardware Clock was not set * before to anything meaningful and regular adjustments have not been done, @@ -996,9 +997,14 @@ static void adjust_drift_factor(struct adjtime *adjtime_p, const struct timeval nowtime, const bool hclock_valid, - const struct timeval hclocktime) + const struct timeval hclocktime, + const bool update) { - if (!hclock_valid) { + if (!update) { + if (debug) + printf(_("Not adjusting drift factor because the " + "--update-drift option was not used.\n")); + } else if (!hclock_valid) { if (debug) printf(_("Not adjusting drift factor because the " "Hardware Clock previously contained " @@ -1016,14 +1022,15 @@ adjust_drift_factor(struct adjtime *adjtime_p, "calibration.\n")); } else if (adjtime_p->last_calib_time != 0) { /* - * At adjustment time we adjust the hardware clock according - * to the contents of /etc/adjtime. + * At adjustment time we drift correct the hardware clock + * according to the contents of the adjtime file and refresh + * its last adjusted timestamp. * - * At calibration time we set the hardware clock and update - * /etc/adjtime, that is, for each calibration (except the - * first) we also do an adjustment. + * At calibration time we set the Hardware Clock and refresh + * both timestamps in <*adjtime_p>. * - * We are now at calibration time. + * Here, with the --update-drift option, we also update the + * drift factor in <*adjtime_p>. * * Let us do computation in doubles. (Floats almost suffice, * but 195 days + 1 second equals 195 days in floats.) @@ -1259,7 +1266,7 @@ manipulate_clock(const bool show, const bool adjust, const bool noadjfile, const bool set, const time_t set_time, const bool hctosys, const bool systohc, const bool systz, const struct timeval startup_time, - const bool utc, const bool local_opt, + const bool utc, const bool local_opt, const bool update, const bool testing, const bool predict, const bool get) { /* Contents of the adjtime file, or what they should be. */ @@ -1364,7 +1371,7 @@ manipulate_clock(const bool show, const bool adjust, const bool noadjfile, adjust_drift_factor(&adjtime, time_inc(t2tv(set_time), time_diff (read_time, startup_time)), - hclock_valid, hclocktime); + hclock_valid, hclocktime, update); } else if (adjust) { if (tdrift.tv_sec > 0 || tdrift.tv_sec < -1) do_adjustment(&adjtime, hclock_valid, @@ -1388,7 +1395,7 @@ manipulate_clock(const bool show, const bool adjust, const bool noadjfile, reftime, universal, testing); if (!noadjfile) adjust_drift_factor(&adjtime, nowtime, - hclock_valid, hclocktime); + hclock_valid, hclocktime, update); } else if (hctosys) { rc = set_system_clock(hclock_valid, hclocktime, testing, universal); @@ -1592,10 +1599,11 @@ static void usage(const char *fmt, ...) " --epoch <year> specifies the year which is the beginning of the\n" " hardware clock's epoch value\n"), _PATH_RTC_DEV); fprintf(usageto, _( + " --update-drift update drift factor in %s\n" " --noadjfile do not access %s; this requires the use of\n" " either --utc or --localtime\n" " --adjfile <file> specifies the path to the adjust file;\n" - " the default is %s\n"), _PATH_ADJTIME, _PATH_ADJTIME); + " the default is %s\n"), _PATH_ADJTIME, _PATH_ADJTIME, _PATH_ADJTIME); fputs(_(" --test do not update anything, just show what would happen\n" " -D, --debug debugging mode\n" "\n"), usageto); #ifdef __alpha__ @@ -1639,7 +1647,7 @@ int main(int argc, char **argv) /* The options debug, badyear and epoch_option are global */ bool show, set, systohc, hctosys, systz, adjust, getepoch, setepoch, predict, compare, get; - bool utc, testing, local_opt, noadjfile, directisa; + bool utc, testing, local_opt, update, noadjfile, directisa; char *date_opt; #ifdef __alpha__ bool ARCconsole, Jensen, SRM, funky_toy; @@ -1659,7 +1667,8 @@ int main(int argc, char **argv) OPT_SET, OPT_SETEPOCH, OPT_SYSTZ, - OPT_TEST + OPT_TEST, + OPT_UPDATE }; static const struct option longopts[] = { @@ -1700,6 +1709,7 @@ int main(int argc, char **argv) {"systz", 0, 0, OPT_SYSTZ}, {"predict-hc", 0, 0, OPT_PREDICT_HC}, {"get", 0, 0, OPT_GET}, + {"update-drift",0, 0, OPT_UPDATE}, {NULL, 0, NULL, 0} }; @@ -1709,6 +1719,7 @@ int main(int argc, char **argv) OPT_SET, OPT_SETEPOCH, OPT_SYSTZ }, { 'u', OPT_LOCALTIME}, { OPT_ADJFILE, OPT_NOADJFILE }, + { OPT_NOADJFILE, OPT_UPDATE }, { 0 } }; int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; @@ -1743,7 +1754,7 @@ int main(int argc, char **argv) /* Set option defaults */ show = set = systohc = hctosys = systz = adjust = noadjfile = predict = - compare = get = FALSE; + compare = get = update = FALSE; getepoch = setepoch = utc = local_opt = directisa = testing = debug = FALSE; #ifdef __alpha__ ARCconsole = Jensen = SRM = funky_toy = badyear = FALSE; @@ -1836,6 +1847,9 @@ int main(int argc, char **argv) case OPT_GET: get = TRUE; /* --get */ break; + case OPT_UPDATE: + update = TRUE; /* --update-drift */ + break; #ifdef __linux__ case 'f': rtc_dev_name = optarg; /* --rtc */ @@ -1950,7 +1964,7 @@ int main(int argc, char **argv) } else rc = manipulate_clock(show, adjust, noadjfile, set, set_time, hctosys, systohc, systz, startup_time, utc, - local_opt, testing, predict, get); + local_opt, update, testing, predict, get); hwclock_exit(rc); return rc; /* Not reached */ |