Move PI step threshold and max frequency settings to common servo code.

These settings will be useful for all implemented servos, so move them
to the common servo code to avoid duplication. The configuration options
are renamed, but the they can be still set by their old names.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
master
Miroslav Lichvar 2014-03-13 18:34:17 +01:00 committed by Richard Cochran
parent 72a9212600
commit 31feb00194
13 changed files with 131 additions and 100 deletions

View File

@ -383,23 +383,26 @@ static enum parser_result parse_global_setting(const char *option,
return r;
*cfg->pi_integral_norm_max = df;
} else if (!strcmp(option, "pi_offset_const")) {
} else if (!strcmp(option, "step_threshold") ||
!strcmp(option, "pi_offset_const")) {
r = get_ranged_double(value, &df, 0.0, DBL_MAX);
if (r != PARSED_OK)
return r;
*cfg->pi_offset_const = df;
*cfg->step_threshold = df;
} else if (!strcmp(option, "pi_f_offset_const")) {
} else if (!strcmp(option, "first_step_threshold") ||
!strcmp(option, "pi_f_offset_const")) {
r = get_ranged_double(value, &df, 0.0, DBL_MAX);
if (r != PARSED_OK)
return r;
*cfg->pi_f_offset_const = df;
*cfg->first_step_threshold = df;
} else if (!strcmp(option, "pi_max_frequency")) {
} else if (!strcmp(option, "max_frequency") ||
!strcmp(option, "pi_max_frequency")) {
r = get_ranged_int(value, &val, 0, INT_MAX);
if (r != PARSED_OK)
return r;
*cfg->pi_max_frequency = val;
*cfg->max_frequency = val;
} else if (!strcmp(option, "sanity_freq_limit")) {
r = get_ranged_int(value, &val, 0, INT_MAX);

View File

@ -77,6 +77,10 @@ struct config {
enum servo_type clock_servo;
double *step_threshold;
double *first_step_threshold;
int *max_frequency;
double *pi_proportional_const;
double *pi_integral_const;
double *pi_proportional_scale;
@ -85,10 +89,6 @@ struct config {
double *pi_integral_scale;
double *pi_integral_exponent;
double *pi_integral_norm_max;
double *pi_offset_const;
double *pi_f_offset_const;
int *pi_max_frequency;
int *sanity_freq_limit;
unsigned char *ptp_dst_mac;

View File

@ -48,9 +48,9 @@ pi_proportional_norm_max 0.7
pi_integral_scale 0.0
pi_integral_exponent 0.4
pi_integral_norm_max 0.3
pi_offset_const 0.0
pi_f_offset_const 0.0000001
pi_max_frequency 900000000
step_threshold 0.0
first_step_threshold 0.0000001
max_frequency 900000000
clock_servo pi
sanity_freq_limit 200000000
#

View File

@ -48,9 +48,9 @@ pi_proportional_norm_max 0.7
pi_integral_scale 0.0
pi_integral_exponent 0.4
pi_integral_norm_max 0.3
pi_offset_const 0.0
pi_f_offset_const 0.0000001
pi_max_frequency 900000000
step_threshold 0.0
first_step_threshold 0.0000001
max_frequency 900000000
clock_servo pi
sanity_freq_limit 200000000
#

View File

@ -96,8 +96,8 @@ Specify the proportional constant of the PI controller. The default is 0.7.
Specify the integral constant of the PI controller. The default is 0.3.
.TP
.BI \-S " step"
Specify the step threshold of the PI controller. It is the maximum offset that
the controller corrects by changing the clock frequency instead of stepping the
Specify the step threshold of the servo. It is the maximum offset that
the servo corrects by changing the clock frequency instead of stepping the
clock. The clock is stepped on start regardless of the option if the offset is
larger than 100 nanoseconds (unless the
.BI \-F

View File

@ -635,12 +635,12 @@ int main(int argc, char *argv[])
return -1;
break;
case 'S':
if (get_arg_val_d(c, optarg, &configured_pi_offset,
if (get_arg_val_d(c, optarg, &servo_step_threshold,
0.0, DBL_MAX))
return -1;
break;
case 'F':
if (get_arg_val_d(c, optarg, &configured_pi_f_offset,
if (get_arg_val_d(c, optarg, &servo_first_step_threshold,
0.0, DBL_MAX))
return -1;
break;

57
pi.c
View File

@ -32,7 +32,6 @@
#define MAX_KP_NORM_MAX 1.0
#define MAX_KI_NORM_MAX 2.0
#define NSEC_PER_SEC 1000000000
#define FREQ_EST_MARGIN 0.001
/* These take their values from the configuration file. (see ptp4l.c) */
@ -44,23 +43,16 @@ double configured_pi_kp_norm_max = 0.7;
double configured_pi_ki_scale = 0.0;
double configured_pi_ki_exponent = 0.4;
double configured_pi_ki_norm_max = 0.3;
double configured_pi_offset = 0.0;
double configured_pi_f_offset = 0.0000001; /* 100 nanoseconds */
int configured_pi_max_freq = 900000000;
struct pi_servo {
struct servo servo;
int64_t offset[2];
uint64_t local[2];
double drift;
double maxppb;
double kp;
double ki;
double max_offset;
double max_f_offset;
double last_freq;
int count;
int first_update;
};
static void pi_destroy(struct servo *servo)
@ -111,19 +103,21 @@ static double pi_sample(struct servo *servo,
/* Adjust drift by the measured frequency offset. */
s->drift += (1e9 - s->drift) * (s->offset[1] - s->offset[0]) /
(s->local[1] - s->local[0]);
if (s->drift < -s->maxppb)
s->drift = -s->maxppb;
else if (s->drift > s->maxppb)
s->drift = s->maxppb;
if ((s->first_update &&
s->max_f_offset && (s->max_f_offset < fabs(offset))) ||
(s->max_offset && (s->max_offset < fabs(offset))))
if (s->drift < -servo->max_frequency)
s->drift = -servo->max_frequency;
else if (s->drift > servo->max_frequency)
s->drift = servo->max_frequency;
if ((servo->first_update &&
servo->first_step_threshold &&
servo->first_step_threshold < fabs(offset)) ||
(servo->step_threshold &&
servo->step_threshold < fabs(offset)))
*state = SERVO_JUMP;
else
*state = SERVO_LOCKED;
s->first_update = 0;
ppb = s->drift;
s->count = 2;
break;
@ -135,7 +129,8 @@ static double pi_sample(struct servo *servo,
* immediately. This allows re-calculating drift as in initial
* clock startup.
*/
if (s->max_offset && (s->max_offset < fabs(offset))) {
if (servo->step_threshold &&
servo->step_threshold < fabs(offset)) {
*state = SERVO_UNLOCKED;
s->count = 0;
break;
@ -143,10 +138,10 @@ static double pi_sample(struct servo *servo,
ki_term = s->ki * offset;
ppb = s->kp * offset + s->drift + ki_term;
if (ppb < -s->maxppb) {
ppb = -s->maxppb;
} else if (ppb > s->maxppb) {
ppb = s->maxppb;
if (ppb < -servo->max_frequency) {
ppb = -servo->max_frequency;
} else if (ppb > servo->max_frequency) {
ppb = servo->max_frequency;
} else {
s->drift += ki_term;
}
@ -181,7 +176,7 @@ static void pi_reset(struct servo *servo)
s->count = 0;
}
struct servo *pi_servo_create(int fadj, int max_ppb, int sw_ts)
struct servo *pi_servo_create(int fadj, int sw_ts)
{
struct pi_servo *s;
@ -195,8 +190,6 @@ struct servo *pi_servo_create(int fadj, int max_ppb, int sw_ts)
s->servo.reset = pi_reset;
s->drift = fadj;
s->last_freq = fadj;
s->maxppb = max_ppb;
s->first_update = 1;
s->kp = 0.0;
s->ki = 0.0;
@ -220,21 +213,5 @@ struct servo *pi_servo_create(int fadj, int max_ppb, int sw_ts)
}
}
if (configured_pi_offset > 0.0) {
s->max_offset = configured_pi_offset * NSEC_PER_SEC;
} else {
s->max_offset = 0.0;
}
if (configured_pi_f_offset > 0.0) {
s->max_f_offset = configured_pi_f_offset * NSEC_PER_SEC;
} else {
s->max_f_offset = 0.0;
}
if (configured_pi_max_freq && s->maxppb > configured_pi_max_freq) {
s->maxppb = configured_pi_max_freq;
}
return &s->servo;
}

26
pi.h
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@ -77,30 +77,6 @@ extern double configured_pi_ki_exponent;
*/
extern double configured_pi_ki_norm_max;
/**
* When set to a non-zero value, this variable controls the maximum allowed
* offset before a clock jump occurs instead of the default clock-slewing
* mechanism.
*
* Note that this variable is measured in seconds, and allows fractional values.
*/
extern double configured_pi_offset;
/**
* When set to zero, the clock is not stepped on start. When set to a non-zero
* value, the value bahaves as a threshold and the clock is stepped on start if
* the offset is bigger than the threshold.
*
* Note that this variable is measured in seconds, and allows fractional values.
*/
extern double configured_pi_f_offset;
/**
* When set to a non-zero value, this variable sets an additional limit for
* the frequency adjustment of the clock. It's in ppb.
*/
extern int configured_pi_max_freq;
struct servo *pi_servo_create(int fadj, int max_ppb, int sw_ts);
struct servo *pi_servo_create(int fadj, int sw_ts);
#endif

22
ptp4l.8
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@ -342,24 +342,30 @@ The ki_norm_max constant in the formula used to set the integral constant of
the PI controller from the sync interval.
The default is 0.3.
.TP
.B pi_offset_const
The maximum offset the PI controller will correct by changing the clock
frequency instead of stepping the clock. When set to 0.0, the controller will
.B step_threshold
The maximum offset the servo will correct by changing the clock
frequency instead of stepping the clock. When set to 0.0, the servo will
never step the clock except on start. It's specified in seconds.
The default is 0.0.
This option used to be called (and can still be set by)
.BR pi_offset_const .
.TP
.B pi_f_offset_const
The maximum offset the PI controller will correct by changing the clock
.B first_step_threshold
The maximum offset the servo will correct by changing the clock
frequency instead of stepping the clock. This is only applied on the first
update. It's specified in seconds. When set to 0.0, the controller won't step
update. It's specified in seconds. When set to 0.0, the servo won't step
the clock on start.
The default is 0.0000001 (100 nanoseconds).
This option used to be called (and can still be set by)
.BR pi_f_offset_const .
.TP
.B pi_max_frequency
.B max_frequency
The maximum allowed frequency adjustment of the clock in parts per billion
(ppb). This is an additional limit to the maximum allowed by the hardware. When
set to 0, the hardware limit will be used.
The default is 900000000 (90%).
This option used to be called (and can still be set by)
.BR pi_max_frequency .
.TP
.B sanity_freq_limit
The maximum allowed frequency offset between uncorrected clock and the system
@ -436,7 +442,7 @@ The default is 00:00:00.
When a leap second is announced, let the kernel apply it by stepping the clock
instead of correcting the one-second offset with servo, which would correct the
one-second offset slowly by changing the clock frequency (unless the
.B pi_offset_const
.B step_threshold
option is set to correct such offset by stepping).
Relevant only with software time stamping. The default is 1 (enabled).
.TP

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@ -104,6 +104,10 @@ static struct config cfg_settings = {
.clock_servo = CLOCK_SERVO_PI,
.step_threshold = &servo_step_threshold,
.first_step_threshold = &servo_first_step_threshold,
.max_frequency = &servo_max_frequency,
.pi_proportional_const = &configured_pi_kp,
.pi_integral_const = &configured_pi_ki,
.pi_proportional_scale = &configured_pi_kp_scale,
@ -112,9 +116,6 @@ static struct config cfg_settings = {
.pi_integral_scale = &configured_pi_ki_scale,
.pi_integral_exponent = &configured_pi_ki_exponent,
.pi_integral_norm_max = &configured_pi_ki_norm_max,
.pi_offset_const = &configured_pi_offset,
.pi_f_offset_const = &configured_pi_f_offset,
.pi_max_frequency = &configured_pi_max_freq,
.ptp_dst_mac = ptp_dst_mac,
.p2p_dst_mac = p2p_dst_mac,

48
servo.c
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@ -21,12 +21,45 @@
#include "pi.h"
#include "servo_private.h"
#define NSEC_PER_SEC 1000000000
double servo_step_threshold = 0.0;
double servo_first_step_threshold = 0.0000001; /* 100 nanoseconds */
int servo_max_frequency = 900000000;
struct servo *servo_create(enum servo_type type, int fadj, int max_ppb, int sw_ts)
{
if (type == CLOCK_SERVO_PI) {
return pi_servo_create(fadj, max_ppb, sw_ts);
struct servo *servo;
switch (type) {
case CLOCK_SERVO_PI:
servo = pi_servo_create(fadj, sw_ts);
break;
default:
return NULL;
}
return NULL;
if (servo_step_threshold > 0.0) {
servo->step_threshold = servo_step_threshold * NSEC_PER_SEC;
} else {
servo->step_threshold = 0.0;
}
if (servo_first_step_threshold > 0.0) {
servo->first_step_threshold =
servo_first_step_threshold * NSEC_PER_SEC;
} else {
servo->first_step_threshold = 0.0;
}
servo->max_frequency = max_ppb;
if (servo_max_frequency && servo->max_frequency > servo_max_frequency) {
servo->max_frequency = servo_max_frequency;
}
servo->first_update = 1;
return servo;
}
void servo_destroy(struct servo *servo)
@ -39,7 +72,14 @@ double servo_sample(struct servo *servo,
uint64_t local_ts,
enum servo_state *state)
{
return servo->sample(servo, offset, local_ts, state);
double r;
r = servo->sample(servo, offset, local_ts, state);
if (*state != SERVO_UNLOCKED)
servo->first_update = 0;
return r;
}
void servo_sync_interval(struct servo *servo, double interval)

24
servo.h
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@ -22,6 +22,30 @@
#include <stdint.h>
/**
* When set to a non-zero value, this variable controls the maximum allowed
* offset before a clock jump occurs instead of the default clock-slewing
* mechanism.
*
* Note that this variable is measured in seconds, and allows fractional values.
*/
extern double servo_step_threshold;
/**
* When set to zero, the clock is not stepped on start. When set to a non-zero
* value, the value bahaves as a threshold and the clock is stepped on start if
* the offset is bigger than the threshold.
*
* Note that this variable is measured in seconds, and allows fractional values.
*/
extern double servo_first_step_threshold;
/**
* When set to a non-zero value, this variable sets an additional limit for
* the frequency adjustment of the clock. It's in ppb.
*/
extern int servo_max_frequency;
/** Opaque type */
struct servo;

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@ -22,6 +22,10 @@
#include "contain.h"
struct servo {
double max_frequency;
double step_threshold;
double first_step_threshold;
int first_update;
void (*destroy)(struct servo *servo);