> -----Original Message-----
> From: Ye, MingjinX <mingjinx...@intel.com>
> Sent: Tuesday 15 October 2024 09:22
> To: dev@dpdk.org
> Cc: Ye, MingjinX <mingjinx...@intel.com>; Su, Simei <simei...@intel.com>;
> Wenjun Wu <wenjun1...@intel.com>; Rybalchenko, Kirill
> <kirill.rybalche...@intel.com>
> Subject: [PATCH v7] examples/ptpclient: add frequency adjustment
>
> This patch adds PI servo controller to support frequency
> adjustment API for IEEE1588 PTP.
>
> For example, the command for starting ptpclient with PI controller is:
> dpdk-ptpclient -a 0000:81:00.0 -c 1 -n 3 -- -T 0 -p 0x1 -c 1
>
> Signed-off-by: Simei Su <simei...@intel.com>
> Signed-off-by: Wenjun Wu <wenjun1...@intel.com>
> Signed-off-by: Mingjin Ye <mingjinx...@intel.com>
Acked-by: Kirill Rybalchenko <kirill.rybalche...@intel.com>
> ---
> v2: Add doc.
> ---
> v3: Enable The servo controller needs to support frequency adjustment.
> ---
> v2: Enable servo controller, PMD must
> support ‘rte_eth_timesync_adjust_freq()’
> API.
> ---
> doc/guides/sample_app_ug/ptpclient.rst | 15 +-
> examples/ptpclient/ptpclient.c | 297 +++++++++++++++++++++++--
> 2 files changed, 289 insertions(+), 23 deletions(-)
>
> diff --git a/doc/guides/sample_app_ug/ptpclient.rst
> b/doc/guides/sample_app_ug/ptpclient.rst
> index d47e942738..014d5f477c 100644
> --- a/doc/guides/sample_app_ug/ptpclient.rst
> +++ b/doc/guides/sample_app_ug/ptpclient.rst
> @@ -50,6 +50,10 @@ The adjustment for slave can be represented as:
> If the command line parameter ``-T 1`` is used the application also
> synchronizes the PTP PHC clock with the Linux kernel clock.
>
> +If the command line parameter ``-c 1`` is used, the application will also
> +use the servo of the local clock. Only one type of servo is currently
> +implemented, the PI controller. Default 0 (not used).
> +
> Compiling the Application
> -------------------------
>
> @@ -65,7 +69,7 @@ To run the example in a ``linux`` environment:
>
> .. code-block:: console
>
> - ./<build_dir>/examples/dpdk-ptpclient -l 1 -n 4 -- -p 0x1 -T 0
> + ./<build_dir>/examples/dpdk-ptpclient -l 1 -n 4 -- -p 0x1 -T 0 -c 1
>
> Refer to *DPDK Getting Started Guide* for general information on running
> applications and the Environment Abstraction Layer (EAL) options.
> @@ -73,7 +77,14 @@ applications and the Environment Abstraction Layer
> (EAL) options.
> * ``-p portmask``: Hexadecimal portmask.
> * ``-T 0``: Update only the PTP slave clock.
> * ``-T 1``: Update the PTP slave clock and synchronize the Linux Kernel to
> the
> PTP clock.
> -
> +* ``-c 0``: Not used clock servo controller.
> +* ``-c 1``: The clock servo PI controller is used and the log will print
> information
> + about "master offset". Note that the PMD needs to support
> + the ``rte_eth_timesync_adjust_freq()`` API to enable the servo
> controller.
> +
> +Also, by adding ``-T 1`` and ``-c 1`` , the ``master offset`` value printed
> in the
> +log will slowly converge and eventually stabilise at the nanosecond level.
> The
> +synchronisation accuracy is much higher compared to not using a servo
> controller.
>
> Code Explanation
> ----------------
> diff --git a/examples/ptpclient/ptpclient.c b/examples/ptpclient/ptpclient.c
> index afb61bba51..e8f6f95f18 100644
> --- a/examples/ptpclient/ptpclient.c
> +++ b/examples/ptpclient/ptpclient.c
> @@ -46,6 +46,35 @@ static volatile bool force_quit;
> #define KERNEL_TIME_ADJUST_LIMIT 20000
> #define PTP_PROTOCOL 0x88F7
>
> +#define KP 0.7
> +#define KI 0.3
> +#define FREQ_EST_MARGIN 0.001
> +
> +enum servo_state {
> + SERVO_UNLOCKED,
> + SERVO_JUMP,
> + SERVO_LOCKED,
> +};
> +
> +struct pi_servo {
> + double offset[2];
> + double local[2];
> + double drift;
> + double last_freq;
> + int count;
> +
> + double max_frequency;
> + double step_threshold;
> + double first_step_threshold;
> + int first_update;
> +};
> +
> +enum controller_mode {
> + MODE_NONE,
> + MODE_PI,
> + MAX_ALL
> +} mode = MODE_NONE;
> +
> struct rte_mempool *mbuf_pool;
> uint32_t ptp_enabled_port_mask;
> uint8_t ptp_enabled_port_nb;
> @@ -135,6 +164,9 @@ struct ptpv2_data_slave_ordinary {
> uint8_t ptpset;
> uint8_t kernel_time_set;
> uint16_t current_ptp_port;
> + int64_t master_offset;
> + int64_t path_delay;
> + struct pi_servo *servo;
> };
>
> static struct ptpv2_data_slave_ordinary ptp_data;
> @@ -262,6 +294,19 @@ port_init(uint16_t port, struct rte_mempool
> *mbuf_pool)
> return retval;
> }
>
> + /*
> + * If the clock servo controller is enabled, the PMD must support
> + * adjustment of the clock frequency.
> + */
> + if (mode != MODE_NONE) {
> + retval = rte_eth_timesync_adjust_freq(port, 0);
> + if (retval == -ENOTSUP) {
> + printf("The servo controller cannot work on devices
> that"
> + " do not support frequency
> adjustment.\n");
> + return retval;
> + }
> + }
> +
> return 0;
> }
>
> @@ -293,36 +338,44 @@ print_clock_info(struct ptpv2_data_slave_ordinary
> *ptp_data)
> ptp_data->tstamp3.tv_sec,
> (ptp_data->tstamp3.tv_nsec));
>
> - printf("\nT4 - Master Clock. %lds %ldns ",
> + printf("\nT4 - Master Clock. %lds %ldns\n",
> ptp_data->tstamp4.tv_sec,
> (ptp_data->tstamp4.tv_nsec));
>
> - printf("\nDelta between master and slave clocks:%"PRId64"ns\n",
> + if (mode == MODE_NONE) {
> + printf("\nDelta between master and slave
> clocks:%"PRId64"ns\n",
> ptp_data->delta);
>
> - clock_gettime(CLOCK_REALTIME, &sys_time);
> - rte_eth_timesync_read_time(ptp_data->current_ptp_port,
> &net_time);
> + clock_gettime(CLOCK_REALTIME, &sys_time);
> + rte_eth_timesync_read_time(ptp_data->current_ptp_port,
> + &net_time);
>
> - time_t ts = net_time.tv_sec;
> + time_t ts = net_time.tv_sec;
>
> - printf("\n\nComparison between Linux kernel Time and PTP:");
> + printf("\n\nComparison between Linux kernel Time and
> PTP:");
>
> - printf("\nCurrent PTP Time: %.24s %.9ld ns",
> + printf("\nCurrent PTP Time: %.24s %.9ld ns",
> ctime(&ts), net_time.tv_nsec);
>
> - nsec = (int64_t)timespec64_to_ns(&net_time) -
> + nsec = (int64_t)timespec64_to_ns(&net_time) -
> (int64_t)timespec64_to_ns(&sys_time);
> - ptp_data->new_adj = ns_to_timeval(nsec);
> + ptp_data->new_adj = ns_to_timeval(nsec);
>
> - gettimeofday(&ptp_data->new_adj, NULL);
> + gettimeofday(&ptp_data->new_adj, NULL);
>
> - time_t tp = ptp_data->new_adj.tv_sec;
> + time_t tp = ptp_data->new_adj.tv_sec;
>
> - printf("\nCurrent SYS Time: %.24s %.6ld ns",
> - ctime(&tp), ptp_data->new_adj.tv_usec);
> + printf("\nCurrent SYS Time: %.24s %.6ld ns",
> + ctime(&tp), ptp_data->new_adj.tv_usec);
>
> - printf("\nDelta between PTP and Linux Kernel time:%"PRId64"ns\n",
> - nsec);
> + printf("\nDelta between PTP and Linux Kernel
> time:%"PRId64"ns\n",
> + nsec);
> + }
> +
> + if (mode == MODE_PI) {
> + printf("path delay: %"PRId64"ns\n", ptp_data->path_delay);
> + printf("master offset: %"PRId64"ns\n", ptp_data-
> >master_offset);
> + }
>
> printf("[Ctrl+C to quit]\n");
>
> @@ -529,6 +582,149 @@ update_kernel_time(void)
>
> }
>
> +static void
> +clock_path_delay(struct ptpv2_data_slave_ordinary *ptp_data)
> +{
> + uint64_t t1_ns, t2_ns, t3_ns, t4_ns;
> + int64_t pd, diff;
> +
> + t1_ns = timespec64_to_ns(&ptp_data->tstamp1);
> + t2_ns = timespec64_to_ns(&ptp_data->tstamp2);
> + t3_ns = timespec64_to_ns(&ptp_data->tstamp3);
> + t4_ns = timespec64_to_ns(&ptp_data->tstamp4);
> +
> + pd = (t2_ns - t3_ns) + (t4_ns - t1_ns);
> + diff = t3_ns - t2_ns;
> + if (diff <= INT32_MAX && diff >= INT32_MIN)
> + ptp_data->path_delay = pd / 2;
> + else
> + ptp_data->path_delay = 0;
> +}
> +
> +static double
> +pi_sample(struct pi_servo *s, int64_t offset, double local_ts,
> + enum servo_state *state)
> +{
> + double ki_term, ppb = s->last_freq;
> + double freq_est_interval, localdiff;
> +
> + switch (s->count) {
> + case 0:
> + s->offset[0] = offset;
> + s->local[0] = local_ts;
> + *state = SERVO_UNLOCKED;
> + s->count = 1;
> + break;
> + case 1:
> + s->offset[1] = offset;
> + s->local[1] = local_ts;
> +
> + /* Make sure the first sample is older than the second. */
> + if (s->local[0] >= s->local[1]) {
> + *state = SERVO_UNLOCKED;
> + s->count = 0;
> + break;
> + }
> +
> + /* Wait long enough before estimating the frequency offset.
> */
> + localdiff = (s->local[1] - s->local[0]) / 1e9;
> + localdiff += localdiff * FREQ_EST_MARGIN;
> + freq_est_interval = 0.016 / KI;
> + if (freq_est_interval > 1000.0)
> + freq_est_interval = 1000.0;
> +
> + if (localdiff < freq_est_interval) {
> + *state = SERVO_UNLOCKED;
> + break;
> + }
> +
> + /* 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->max_frequency)
> + s->drift = -s->max_frequency;
> + else if (s->drift > s->max_frequency)
> + s->drift = s->max_frequency;
> +
> + if ((s->first_update &&
> + s->first_step_threshold &&
> + s->first_step_threshold < llabs(offset)) ||
> + (s->step_threshold &&
> + s->step_threshold < llabs(offset)))
> + *state = SERVO_JUMP;
> + else
> + *state = SERVO_LOCKED;
> +
> + ppb = s->drift;
> + s->count = 2;
> + break;
> + case 2:
> + /*
> + * reset the clock servo when offset is greater than the max
> + * offset value. Note that the clock jump will be performed in
> + * step 1, so it is not necessary to have clock jump
> + * immediately. This allows re-calculating drift as in initial
> + * clock startup.
> + */
> + if (s->step_threshold &&
> + s->step_threshold < llabs(offset)) {
> + *state = SERVO_UNLOCKED;
> + s->count = 0;
> + break;
> + }
> +
> + ki_term = KI * offset;
> + ppb = KP * offset + s->drift + ki_term;
> + if (ppb < -s->max_frequency)
> + ppb = -s->max_frequency;
> + else if (ppb > s->max_frequency)
> + ppb = s->max_frequency;
> + else
> + s->drift += ki_term;
> +
> + *state = SERVO_LOCKED;
> + break;
> + }
> +
> + s->last_freq = ppb;
> + return ppb;
> +}
> +
> +static void
> +ptp_adjust_servo(struct ptpv2_data_slave_ordinary *ptp_data)
> +{
> + uint64_t t1_ns, t2_ns;
> + double adj_freq;
> + enum servo_state state = SERVO_UNLOCKED;
> +
> + t1_ns = timespec64_to_ns(&ptp_data->tstamp1);
> + t2_ns = timespec64_to_ns(&ptp_data->tstamp2);
> + ptp_data->master_offset = t2_ns - t1_ns - ptp_data->path_delay;
> + if (!ptp_data->path_delay)
> + return;
> +
> + adj_freq = pi_sample(ptp_data->servo, ptp_data->master_offset,
> t2_ns,
> + &state);
> +
> + switch (state) {
> + case SERVO_UNLOCKED:
> + break;
> + case SERVO_JUMP:
> + ptp_data->servo->first_update = 0;
> + rte_eth_timesync_adjust_freq(ptp_data->portid,
> + -(long)(adj_freq * 65.536));
> + rte_eth_timesync_adjust_time(ptp_data->portid,
> + -ptp_data->master_offset);
> + break;
> + case SERVO_LOCKED:
> + ptp_data->servo->first_update = 0;
> + rte_eth_timesync_adjust_freq(ptp_data->portid,
> + -(long)(adj_freq * 65.536));
> + break;
> + }
> +}
> +
> /*
> * Parse the DELAY_RESP message.
> */
> @@ -553,11 +749,16 @@ parse_drsp(struct ptpv2_data_slave_ordinary
> *ptp_data)
> ((uint64_t)ntohl(rx_tstamp->sec_lsb)) |
> (((uint64_t)ntohs(rx_tstamp->sec_msb)) <<
> 32);
>
> - /* Evaluate the delta for adjustment. */
> - ptp_data->delta = delta_eval(ptp_data);
> + if (mode == MODE_PI) {
> + clock_path_delay(ptp_data);
> + ptp_adjust_servo(ptp_data);
> + } else {
> + /* Evaluate the delta for adjustment. */
> + ptp_data->delta = delta_eval(ptp_data);
>
> - rte_eth_timesync_adjust_time(ptp_data->portid,
> - ptp_data->delta);
> + rte_eth_timesync_adjust_time(ptp_data-
> >portid,
> + ptp_data-
> >delta);
> + }
>
> ptp_data->current_ptp_port = ptp_data->portid;
>
> @@ -652,7 +853,9 @@ print_usage(const char *prgname)
> printf("%s [EAL options] -- -p PORTMASK -T VALUE\n"
> " -T VALUE: 0 - Disable, 1 - Enable Linux Clock"
> " Synchronization (0 default)\n"
> - " -p PORTMASK: hexadecimal bitmask of ports to
> configure\n",
> + " -p PORTMASK: hexadecimal bitmask of ports to configure\n"
> + " -c CONTROLLER: 0 - Not used, 1 - PI. The servo which is"
> + " used to synchronize the local clock. (0 default)\n",
> prgname);
> }
>
> @@ -688,6 +891,36 @@ parse_ptp_kernel(const char *param)
> return 1;
> }
>
> +static int
> +parse_ptp_servo_mode(const char *param)
> +{
> + char *end = NULL;
> + unsigned long pm;
> +
> + /* Parse the hexadecimal string. */
> + pm = strtoul(param, &end, 10);
> +
> + if ((param[0] == '\0') || (end == NULL) || (*end != '\0'))
> + return -1;
> +
> + return pm;
> +}
> +
> +static void
> +servo_init(struct pi_servo *servo)
> +{
> + memset(servo, 0x00, sizeof(*servo));
> +
> + servo->drift = 100000000;
> + servo->last_freq = 100000000;
> + servo->count = 0;
> +
> + servo->max_frequency = 100000000;
> + servo->step_threshold = 0.1 * NSEC_PER_SEC;
> + servo->first_step_threshold = 0.00002 * NSEC_PER_SEC;
> + servo->first_update = 1;
> +}
> +
> /* Parse the commandline arguments. */
> static int
> ptp_parse_args(int argc, char **argv)
> @@ -700,7 +933,7 @@ ptp_parse_args(int argc, char **argv)
>
> argvopt = argv;
>
> - while ((opt = getopt_long(argc, argvopt, "p:T:",
> + while ((opt = getopt_long(argc, argvopt, "p:T:c:",
> lgopts, &option_index)) != EOF) {
>
> switch (opt) {
> @@ -724,6 +957,17 @@ ptp_parse_args(int argc, char **argv)
>
> ptp_data.kernel_time_set = ret;
> break;
> + case 'c':
> + ret = parse_ptp_servo_mode(optarg);
> + if (ret == 0) {
> + mode = MODE_NONE;
> + } else if (ret == 1) {
> + mode = MODE_PI;
> + } else {
> + print_usage(prgname);
> + return -1;
> + }
> + break;
>
> default:
> print_usage(prgname);
> @@ -778,6 +1022,14 @@ main(int argc, char *argv[])
> rte_exit(EXIT_FAILURE, "Error with PTP initialization\n");
> /* >8 End of parsing specific arguments. */
>
> + if (mode == MODE_PI) {
> + ptp_data.servo = malloc(sizeof(*(ptp_data.servo)));
> + if (!ptp_data.servo)
> + rte_exit(EXIT_FAILURE, "no memory for servo\n");
> +
> + servo_init(ptp_data.servo);
> + }
> +
> /* Check that there is an even number of ports to send/receive on. */
> nb_ports = rte_eth_dev_count_avail();
>
> @@ -831,6 +1083,9 @@ main(int argc, char *argv[])
> rte_eth_dev_close(portid);
> }
>
> + if (mode == MODE_PI)
> + free(ptp_data.servo);
> +
> /* clean up the EAL */
> rte_eal_cleanup();
>
> --
> 2.25.1
