diff options
Diffstat (limited to 'hwclock/adjtime.patch')
| -rw-r--r-- | hwclock/adjtime.patch | 302 |
1 files changed, 0 insertions, 302 deletions
diff --git a/hwclock/adjtime.patch b/hwclock/adjtime.patch deleted file mode 100644 index 81d0430fd..000000000 --- a/hwclock/adjtime.patch +++ /dev/null @@ -1,302 +0,0 @@ -From ao112@rgfn.epcc.edu Fri Mar 19 06:27:26 1999 -Received: from rgfn.epcc.edu (rgfn.epcc.edu [208.136.234.19]) by hera.cwi.nl with ESMTP - id GAA27711 for <Andries.Brouwer@cwi.nl>; Fri, 19 Mar 1999 06:27:23 +0100 (MET) -Received: (from ao112@localhost) - by rgfn.epcc.edu (8.8.8/8.8.8) id WAA16797; - Thu, 18 Mar 1999 22:27:19 -0700 (MST) -Date: Thu, 18 Mar 1999 22:27:19 -0700 (MST) -Message-Id: <199903190527.WAA16797@rgfn.epcc.edu> -From: ao112@rgfn.epcc.edu (James P. Rutledge) -To: Andries.Brouwer@cwi.nl -Subject: Re: hwclock patch for drift_factor calculation improvement -Reply-To: ao112@rgfn.epcc.edu -Status: R - - - -> ->Could you perhaps make your patch relative to ->util-linux-2.9n (found in ftp.cwi.nl/pub/aeb/util-linux/util-linux-2.9n.tar.gz) ->? -> ->(The hwclock stuff has changed quite a bit since 2.9g.) -> ->Andries -> - -Andries; - -Per your request, the patch has been modified for util-linux version -2.9n, from the version for 2.9g. - -The program "hwclock" (version 2.4c) could give more accurate -values for the drift factor that it places in the file "/etc/adjtime". - -A patch to improve the accuracy is included. - -I have incorporated some error sources which were not compensated -for into the drift factor calculation (performed when the "--set" -or the "--systohc" option is used) to make it more accurate. -In particular, the sync delay between the desired set time and the -start of the hardware clock second, and the expected drift since the -last hardware clock adjustment are now accounted for in the drift -factor calculation. - -With this patch, if at any time an adjust operation is attempted and -the hardware clock is found to be not valid, then the calibration -and adjustment time is set to zero to insure that if the hardware -clock should coincidentally return to validity, a calibration is not -done with bad history data (hardware clock info bad) and an adjust is -not attempted on bad (but now passing validity test) hardware clock -data. (With this patch, a previous calibration time of zero causes -the calibration time to initialize with the current time, when the -hardware clock is set, but no change is made to the drift factor, -so in effect, an initial calibration is started over while the previous -drift factor is retained.) - -Also, the behavior in the case of an initially missing "/etc/adjtime" -file or such a file produced by the predecessor "clock" program has -been slightly improved as follows: - - With this patch, if the file exists but was produced by "clock" - and, thus, is given a zero calibration time, the drift factor is - not updated upon the first calibration by "hwclock", but is left alone - and is only changed by subsequent calibrations. - - With this patch, if the file does not exist and, thus, is given - a zero calibration time, the drift factor is set to zero upon the - first calibration by "hwclock" and is then changed, as appropriate, by - subsequent calibrations. - - Also, with this patch, an "--adjust" operation against a non-existent - "/etc/adjtime" file or one which has zero as the last adjustment - time will not change the hardware clock setting. - -A context diff for a patch to the file "hwclock.c" in the directory -"util-linux-2.9n/clock" is appended. -To use the patch, "cd" to the directory "util-linux-2.9n/clock". -Run "patch < bug-report", where "bug-report" is the file name of -this mail message, to get new file "hwclock.c" which contains the proposed -new version. This patch is, of course, submitted per the GPL and the -appropriate "NO WARRANTY OF ANY KIND" and "USE AT YOUR OWN RISK" -disclaimers apply. - -Note that the patch presumptuously changes the "hwclock.c" version -number from 2.4c to 2.4c1 in "hwclock.c". - -Jim - ------------------- Patch file follows ---------------------------- -*** hwclock.c Thu Mar 18 22:04:01 1999 ---- new-hwclock.c Thu Mar 18 22:03:18 1999 -*************** -*** 76,86 **** - - #include "clock.h" - #include "../version.h" - - #define MYNAME "hwclock" -! #define VERSION "2.4c" - - char *progname = MYNAME; - - /* The struct that holds our hardware access routines */ - struct clock_ops *ur; ---- 76,86 ---- - - #include "clock.h" - #include "../version.h" - - #define MYNAME "hwclock" -! #define VERSION "2.4c1" - - char *progname = MYNAME; - - /* The struct that holds our hardware access routines */ - struct clock_ops *ur; -*************** -*** 581,601 **** - - - static void - adjust_drift_factor(struct adjtime *adjtime_p, - const time_t nowtime, -! const bool hclock_valid, const time_t hclocktime ) { - /*--------------------------------------------------------------------------- - 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>. - -- We assume that the user has been doing regular drift adjustments -- using the drift factor in the adjtime file, so if <nowtime> and -- <clocktime> are different, that means the adjustment factor isn't -- quite right. -- - 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. - - EXCEPT: if <hclock_valid> is false, assume Hardware Clock was not set - before to anything meaningful and regular adjustments have not been ---- 581,598 ---- - - - static void - adjust_drift_factor(struct adjtime *adjtime_p, - const time_t nowtime, -! const bool hclock_valid, -! const time_t hclocktime, -! const float sync_delay ) { - /*--------------------------------------------------------------------------- - 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>. - - 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. - - EXCEPT: if <hclock_valid> is false, assume Hardware Clock was not set - before to anything meaningful and regular adjustments have not been -*************** -*** 604,629 **** - ----------------------------------------------------------------------------*/ - if (!hclock_valid) { - if (debug) - printf("Not adjusting drift factor because the Hardware Clock " - "previously contained garbage.\n"); - } else if ((hclocktime - adjtime_p->last_calib_time) < 23 * 60 * 60) { - if (debug) - printf("Not adjusting drift factor because it has been less than a " - "day since the last calibration.\n"); - } else { -! const float factor_adjust = -! ((float) (nowtime - hclocktime) -! / (hclocktime - adjtime_p->last_calib_time)) -! * 24 * 60 * 60; - - if (debug) -! printf("Clock drifted %d seconds in the past %d seconds " - "in spite of a drift factor of %f seconds/day.\n" - "Adjusting drift factor by %f seconds/day\n", -! (int) (nowtime - hclocktime), -! (int) (hclocktime - adjtime_p->last_calib_time), - adjtime_p->drift_factor, - factor_adjust ); - - adjtime_p->drift_factor += factor_adjust; - } ---- 601,642 ---- - ----------------------------------------------------------------------------*/ - if (!hclock_valid) { - if (debug) - printf("Not adjusting drift factor because the Hardware Clock " - "previously contained garbage.\n"); -+ } else if (adjtime_p->last_calib_time == 0) { -+ if (debug) -+ printf("Not adjusting drift factor because last calibration " -+ "time is zero,\nso history is bad and calibration startover " -+ "is necessary.\n"); - } else if ((hclocktime - adjtime_p->last_calib_time) < 23 * 60 * 60) { - if (debug) - printf("Not adjusting drift factor because it has been less than a " - "day since the last calibration.\n"); - } else { -! const float sec_per_day = 24.0 * 60.0 * 60.0; -! float atime_per_htime; /* adjusted time units per hardware time unit */ -! float adj_days; /* days since last adjustment (in hardware clock time) */ -! float cal_days; /* days since last calibration (in hardware clock time) */ -! float exp_drift; /* expected drift (sec) since last adjustment */ -! float unc_drift; /* uncorrected drift (sec) since last calibration */ -! float factor_adjust; /* amount to add to previous drift factor */ -! atime_per_htime = 1.0 + adjtime_p->drift_factor / sec_per_day; -! adj_days = (float)(hclocktime - adjtime_p->last_adj_time) / sec_per_day; -! exp_drift = adj_days * adjtime_p->drift_factor + adjtime_p->not_adjusted; -! unc_drift = (float)(nowtime - hclocktime) + sync_delay - exp_drift; -! cal_days = ((float)(adjtime_p->last_adj_time - adjtime_p->last_calib_time) -! + adjtime_p->not_adjusted) / (sec_per_day * atime_per_htime) -! + adj_days; -! factor_adjust = unc_drift / cal_days; - - if (debug) -! printf("Clock drifted %.1f seconds in the past %d seconds " - "in spite of a drift factor of %f seconds/day.\n" - "Adjusting drift factor by %f seconds/day\n", -! unc_drift, -! (int) (nowtime - adjtime_p->last_calib_time), - adjtime_p->drift_factor, - factor_adjust ); - - adjtime_p->drift_factor += factor_adjust; - } -*************** -*** 764,773 **** ---- 777,794 ---- - - ----------------------------------------------------------------------------*/ - if (!hclock_valid) { - fprintf(stderr, "The Hardware Clock does not contain a valid time, " - "so we cannot adjust it.\n"); -+ adjtime_p->last_calib_time = 0; /* calibration startover is required */ -+ adjtime_p->last_adj_time = 0; -+ adjtime_p->not_adjusted = 0; -+ adjtime_p->dirty = TRUE; -+ } else if (adjtime_p->last_adj_time == 0) { -+ if (debug) -+ printf("Not setting clock because last adjustment time is zero, " -+ "so history is bad."); - } else { - int adjustment; - /* Number of seconds we must insert in the Hardware Clock */ - float retro; - /* Fraction of second we have to remove from clock after inserting -*************** -*** 878,888 **** - time_diff(read_time, startup_time)); - *retcode_p = 0; - } else if (set) { - set_hardware_clock_exact(set_time, startup_time, - universal, testing); -! adjust_drift_factor(&adjtime, set_time, hclock_valid, hclocktime); - *retcode_p = 0; - } else if (adjust) { - do_adjustment(&adjtime, hclock_valid, hclocktime, - read_time, universal, testing); - *retcode_p = 0; ---- 899,910 ---- - time_diff(read_time, startup_time)); - *retcode_p = 0; - } else if (set) { - set_hardware_clock_exact(set_time, startup_time, - universal, testing); -! adjust_drift_factor(&adjtime, set_time, hclock_valid, hclocktime, -! time_diff(read_time, startup_time)); - *retcode_p = 0; - } else if (adjust) { - do_adjustment(&adjtime, hclock_valid, hclocktime, - read_time, universal, testing); - *retcode_p = 0; -*************** -*** 898,908 **** - - set_hardware_clock_exact((time_t) reftime.tv_sec, reftime, - universal, testing); - *retcode_p = 0; - adjust_drift_factor(&adjtime, (time_t) reftime.tv_sec, hclock_valid, -! hclocktime); - } else if (hctosys) { - rc = set_system_clock(hclock_valid, hclocktime, testing); - if (rc != 0) { - printf("Unable to set system clock.\n"); - *retcode_p = 1; ---- 920,930 ---- - - set_hardware_clock_exact((time_t) reftime.tv_sec, reftime, - universal, testing); - *retcode_p = 0; - adjust_drift_factor(&adjtime, (time_t) reftime.tv_sec, hclock_valid, -! hclocktime, (float)(read_time.tv_usec / 1E6)); - } else if (hctosys) { - rc = set_system_clock(hclock_valid, hclocktime, testing); - if (rc != 0) { - printf("Unable to set system clock.\n"); - *retcode_p = 1; - |