Delay asymmetry calculation based on the PTP port interface speed of
master obtained from TLV and the slave interface rate obtained by ethtool.
The calculation is done in attoseconds to accomodate interface bit period
less than 1ns. (ITU-T G.8275.2(06/2021) annex D).
v4: removing bit period calculation on every signalling message and updating
the bit-period when link update happens
v3: updating network/host byte order handling.
v1: initial commit
Signed-off-by: Greg Armstrong <greg.armstrong...@renesas.com>
Signed-off-by: Leon Goldin <leon.goldin...@renesas.com>
Signed-off-by: Devasish Dey <devasish....@syncmonk.net>
Signed-off-by: Vipin Sharma <vipin.sha...@syncmonk.net>
---
interface.c | 5 +++++
interface.h | 7 +++++++
port_private.h | 1 +
port_signaling.c | 39 ++++++++++++++++++++++++++++++++++++---
ptp4l.8 | 7 +++++++
tlv.c | 29 +++++++++++++++++++++++++++++
unicast_service.c | 32 ++++++++++++++++++++++++++++++++
7 files changed, 117 insertions(+), 3 deletions(-)
diff --git a/interface.c b/interface.c
index 8524719..29229ad 100644
--- a/interface.c
+++ b/interface.c
@@ -94,3 +94,8 @@ int interface_get_vclock(struct interface *iface)
{
return iface->vclock;
}
+
+uint64_t interface_bitperiod(struct interface *iface)
+{
+ return iface->if_info.iface_bit_period;
+}
diff --git a/interface.h b/interface.h
index 5289a7f..0873bba 100644
--- a/interface.h
+++ b/interface.h
@@ -113,4 +113,11 @@ void interface_set_vclock(struct interface *iface, int
vclock);
*/
int interface_get_vclock(struct interface *iface);
+/**
+ * Obtains the interface bit period based on the speed.
+ * @param iface The interface of interest.
+ * @return return interface bitperiod in atto seconds.
+ */
+uint64_t interface_bitperiod(struct interface *iface);
+
#endif
diff --git a/port_private.h b/port_private.h
index d6487eb..6ad4af8 100644
--- a/port_private.h
+++ b/port_private.h
@@ -146,6 +146,7 @@ struct port {
UInteger8 delay_response_counter;
UInteger8 delay_response_timeout;
bool iface_rate_tlv;
+ Integer64 portAsymmetry;
struct PortStats stats;
struct PortServiceStats service_stats;
/* foreignMasterDS */
diff --git a/port_signaling.c b/port_signaling.c
index ed217c0..5a764d6 100644
--- a/port_signaling.c
+++ b/port_signaling.c
@@ -103,10 +103,37 @@ static int process_interval_request(struct port *p,
return 0;
}
+static int process_interface_rate(struct port *p,
+ struct msg_interface_rate_tlv *r)
+{
+ Integer64 delayAsymmetry;
+ double nsDelay;
+ Integer64 slaveBitPeriod;
+ Integer64 masterBitPeriod;
+
+ if (p->iface_rate_tlv && interface_ifinfo_valid(p->iface)) {
+ slaveBitPeriod = interface_bitperiod(p->iface);
+ masterBitPeriod = r->interfaceBitPeriod;
+
+ /* Delay Asymmetry Calculation */
+ nsDelay = (double)(masterBitPeriod - slaveBitPeriod) / (2 *
1.0e9);
+ delayAsymmetry =
+ (r->numberOfBitsAfterTimestamp -
r->numberOfBitsBeforeTimestamp) * nsDelay;
+
+ if (delayAsymmetry != p->portAsymmetry) {
+ p->asymmetry += ((delayAsymmetry - p->portAsymmetry) <<
16);
+ p->portAsymmetry = delayAsymmetry;
+ }
+ }
+ return 0;
+}
+
int process_signaling(struct port *p, struct ptp_message *m)
{
struct tlv_extra *extra;
+ struct organization_tlv *org;
struct msg_interval_req_tlv *r;
+ struct msg_interface_rate_tlv *rate;
int err = 0, result;
switch (p->state) {
@@ -160,11 +187,17 @@ int process_signaling(struct port *p, struct ptp_message
*m)
break;
case TLV_ORGANIZATION_EXTENSION:
- r = (struct msg_interval_req_tlv *) extra->tlv;
+ org = (struct organization_tlv *)extra->tlv;
- if (0 == memcmp(r->id, ieee8021_id,
sizeof(ieee8021_id)) &&
- r->subtype[0] == 0 && r->subtype[1] == 0 &&
r->subtype[2] == 2)
+ if (0 == memcmp(org->id, ieee8021_id,
sizeof(ieee8021_id)) &&
+ org->subtype[0] == 0 && org->subtype[1] == 0 &&
org->subtype[2] == 2) {
+ r = (struct msg_interval_req_tlv *) extra->tlv;
err = process_interval_request(p, r);
+ } else if (0 == memcmp(org->id, itu_t_id,
sizeof(itu_t_id)) &&
+ org->subtype[0] == 0 && org->subtype[1] == 0
&& org->subtype[2] == 2) {
+ rate = (struct msg_interface_rate_tlv *)
extra->tlv;
+ err = process_interface_rate(p, rate);
+ }
break;
}
}
diff --git a/ptp4l.8 b/ptp4l.8
index cd6299f..e96d090 100644
--- a/ptp4l.8
+++ b/ptp4l.8
@@ -697,6 +697,13 @@ The default is 0 (disabled).
Print messages to the system log if enabled.
The default is 1 (enabled).
.TP
+.B interface_rate_tlv
+When the client and server are operating are operating at different interface
rate,
+delay asymmetry caused due to different interface rate needs to be compensated.
+The server sends its interface rate using interface rate TLV
+as per G.8275.2 Annex D.
+The default is 0 (does not support interface rate tlv).
+.TP
.B summary_interval
The time interval in which are printed summary statistics of the clock. It is
specified as a power of two in seconds. The statistics include offset root mean
diff --git a/tlv.c b/tlv.c
index 35bee4f..7a2a4fa 100644
--- a/tlv.c
+++ b/tlv.c
@@ -681,6 +681,7 @@ static void nsm_resp_pre_send(struct tlv_extra *extra)
static int org_post_recv(struct organization_tlv *org)
{
struct follow_up_info_tlv *f;
+ struct msg_interface_rate_tlv *m;
if (0 == memcmp(org->id, ieee8021_id, sizeof(ieee8021_id))) {
if (org->subtype[0] || org->subtype[1]) {
@@ -701,6 +702,21 @@ static int org_post_recv(struct organization_tlv *org)
if (org->length + sizeof(struct TLV) != sizeof(struct
msg_interval_req_tlv))
goto bad_length;
}
+ } else if (0 == memcmp(org->id, itu_t_id, sizeof(itu_t_id))) {
+ if (org->subtype[0] || org->subtype[1]) {
+ return 0;
+ }
+ switch (org->subtype[2]) {
+ case 2:
+ if (org->length + sizeof(struct TLV) != sizeof(struct
msg_interface_rate_tlv))
+ goto bad_length;
+ m = (struct msg_interface_rate_tlv *)org;
+ m->interfaceBitPeriod =
net2host64(m->interfaceBitPeriod);
+ m->numberOfBitsBeforeTimestamp =
ntohs(m->numberOfBitsBeforeTimestamp);
+ m->numberOfBitsAfterTimestamp =
ntohs(m->numberOfBitsAfterTimestamp);
+ break;
+ }
+
}
return 0;
bad_length:
@@ -710,6 +726,7 @@ bad_length:
static void org_pre_send(struct organization_tlv *org)
{
struct follow_up_info_tlv *f;
+ struct msg_interface_rate_tlv *m;
if (0 == memcmp(org->id, ieee8021_id, sizeof(ieee8021_id))) {
if (org->subtype[0] || org->subtype[1]) {
@@ -724,6 +741,18 @@ static void org_pre_send(struct organization_tlv *org)
f->scaledLastGmPhaseChange =
htonl(f->scaledLastGmPhaseChange);
break;
}
+ } else if (0 == memcmp(org->id, itu_t_id, sizeof(itu_t_id))) {
+ if (org->subtype[0] || org->subtype[1]) {
+ return;
+ }
+ switch (org->subtype[2]) {
+ case 2:
+ m = (struct msg_interface_rate_tlv *)org;
+ m->interfaceBitPeriod =
host2net64(m->interfaceBitPeriod);
+ m->numberOfBitsBeforeTimestamp =
htons(m->numberOfBitsBeforeTimestamp);
+ m->numberOfBitsAfterTimestamp =
htons(m->numberOfBitsAfterTimestamp);
+ break;
+ }
}
}
diff --git a/unicast_service.c b/unicast_service.c
index 3154894..1078041 100644
--- a/unicast_service.c
+++ b/unicast_service.c
@@ -84,6 +84,30 @@ static int attach_grant(struct ptp_message *msg,
return 0;
}
+static int attach_interface_rate(struct ptp_message *msg,
+ uint64_t iface_bit_period,
+ uint16_t no_of_bits_before_ts,
+ uint16_t no_of_bits_after_ts)
+{
+ struct msg_interface_rate_tlv *mir;
+ struct tlv_extra *extra;
+
+ extra = msg_tlv_append(msg, sizeof(*mir));
+ if (!extra) {
+ return -1;
+ }
+ mir = (struct msg_interface_rate_tlv *) extra->tlv;
+ mir->type = TLV_ORGANIZATION_EXTENSION;
+ mir->length = sizeof(*mir) - sizeof(mir->type) - sizeof(mir->length);
+ memcpy(mir->id, itu_t_id, sizeof(itu_t_id));
+ mir->subtype[2] = 2;
+ mir->interfaceBitPeriod = iface_bit_period;
+ mir->numberOfBitsBeforeTimestamp = no_of_bits_before_ts;
+ mir->numberOfBitsAfterTimestamp = no_of_bits_after_ts;
+
+ return 0;
+}
+
static int compare_timeout(void *ain, void *bin)
{
struct unicast_service_interval *a, *b;
@@ -256,6 +280,14 @@ static int unicast_service_reply(struct port *p, struct
ptp_message *dst,
if (err) {
goto out;
}
+ if (p->iface_rate_tlv && duration > 0 &&
interface_ifinfo_valid(p->iface)) {
+ err = attach_interface_rate(msg,
+ interface_bitperiod(p->iface), 64, 720);
+ if (err) {
+ goto out;
+ }
+ }
+
err = port_prepare_and_send(p, msg, TRANS_GENERAL);
if (err) {
pr_err("%s: signaling message failed", p->log_name);
--
2.34.1
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