* Re: About timestamping and can-utils
2014-03-06 9:25 About timestamping and can-utils Stephane Grosjean
@ 2014-03-06 9:56 ` Oliver Hartkopp
2014-03-06 11:03 ` Stephane Grosjean
0 siblings, 1 reply; 4+ messages in thread
From: Oliver Hartkopp @ 2014-03-06 9:56 UTC (permalink / raw)
To: Stephane Grosjean; +Cc: linux-can@vger.kernel.org
[-- Attachment #1: Type: text/plain, Size: 1976 bytes --]
Hi Stephane,
here's a discussion thread from last year focussing HW timestamping:
http://marc.info/?l=linux-can&m=138210737431112&w=2
Additionally I attached two patches:
cants-test.patch:
added some functionality to add a monotonic (sw) timestamp to sja1000
candump-hwts.patch:
added some functionality to candump to get these timestamps
The candump patch is from the time before the include file cleanup inside the
can-utils provided by Uwe. (including from socketcan directory)
Together with the discussion thread from above, this should give a good
starting point.
Regards,
Oliver
On 06.03.2014 10:25, Stephane Grosjean wrote:
> Hi linux-can team,
>
> I've got one question about how timestamping is done now in linux-can,
> regarding to HW timestamps.
>
> In the early ages (~v3.4), the CAN hardware driver could set the timestamp of
> an skb by itself and push it with the received CAN frame, so that the
> application could get it using SO_TIMESTAMP socket option, right?
> Now, this "hardware" timestamp is to be copied into "hwstamp" field of the
> "skb_hwtstamps(skb)" area.
>
> But how does user application manage to get this hardware timestamp on its
> side? AFAIK, the "candump" can-utils utility always reads and displays the
> "network" timestamp (that is, always uses SO_TIMESTAMP socket option). I had a
> quick look to the Kernel sources and tried to find the links between things
> but it's not very clear to me: first idea I tested was to set the
> SO_TIMESTAMPING socket option, but candump never received any hw timestamp in
> the control messages he reads from the CAN socket...
>
> Any help would be appreciated.
>
> Regards,
>
> Stéphane
> --
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> --
[-- Attachment #2: cants-test.patch --]
[-- Type: text/x-diff, Size: 1529 bytes --]
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 7164a99..57b5d44 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -326,6 +326,8 @@ static void sja1000_rx(struct net_device *dev)
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
+ struct timespec tsraw, tsreal;
+ struct skb_shared_hwtstamps *hwts;
uint8_t fi;
uint8_t dreg;
canid_t id;
@@ -366,6 +368,11 @@ static void sja1000_rx(struct net_device *dev)
/* release receive buffer */
sja1000_write_cmdreg(priv, CMD_RRB);
+ getnstime_raw_and_real(&tsraw, &tsreal);
+ skb->tstamp = timespec_to_ktime(tsreal);
+ hwts = skb_hwtstamps(skb);
+ hwts->syststamp = timespec_to_ktime(tsraw);
+
netif_rx(skb);
stats->rx_packets++;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 947ba25..19fc013 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -431,8 +431,6 @@ ktime_t ktime_get_clocktai(void)
}
EXPORT_SYMBOL(ktime_get_clocktai);
-#ifdef CONFIG_NTP_PPS
-
/**
* getnstime_raw_and_real - get day and raw monotonic time in timespec format
* @ts_raw: pointer to the timespec to be set to raw monotonic time
@@ -467,8 +465,6 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
}
EXPORT_SYMBOL(getnstime_raw_and_real);
-#endif /* CONFIG_NTP_PPS */
-
/**
* do_gettimeofday - Returns the time of day in a timeval
* @tv: pointer to the timeval to be set
[-- Attachment #3: candump-hwts.patch --]
[-- Type: text/x-diff, Size: 9658 bytes --]
diff --git a/Makefile b/Makefile
index 2f79ee7..40067fb 100644
--- a/Makefile
+++ b/Makefile
@@ -45,6 +45,7 @@ MAKEFLAGS = -k
CFLAGS = -O2 -Wall -Wno-parentheses -Iinclude \
-fno-strict-aliasing \
+ -DSO_TIMESTAMPING=37 \
-DSO_RXQ_OVFL=40 \
-DPF_CAN=29 \
-DAF_CAN=PF_CAN
diff --git a/candump.c b/candump.c
index c865bd7..d7723d8 100644
--- a/candump.c
+++ b/candump.c
@@ -60,6 +60,7 @@
#include <linux/can.h>
#include <linux/can/raw.h>
+#include <linux/net_tstamp.h>
#include "terminal.h"
#include "lib.h"
@@ -106,7 +107,8 @@ void print_usage(char *prg)
{
fprintf(stderr, "\nUsage: %s [options] <CAN interface>+\n", prg);
fprintf(stderr, " (use CTRL-C to terminate %s)\n\n", prg);
- fprintf(stderr, "Options: -t <type> (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)\n");
+ fprintf(stderr, "Options: -t <type> (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date )\n");
+ fprintf(stderr, " ( (r)aw hardware/(s)ystem hardware transformed)\n");
fprintf(stderr, " -c (increment color mode level)\n");
fprintf(stderr, " -i (binary output - may exceed 80 chars/line)\n");
fprintf(stderr, " -a (enable additional ASCII output)\n");
@@ -219,7 +221,10 @@ int main(int argc, char **argv)
int currmax, numfilter;
char *ptr, *nptr;
struct sockaddr_can addr;
- char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
+ struct {
+ struct cmsghdr cm;
+ char control[512];
+ } control;
struct iovec iov;
struct msghdr msg;
struct cmsghdr *cmsg;
@@ -228,7 +233,8 @@ int main(int argc, char **argv)
struct canfd_frame frame;
int nbytes, i, maxdlen;
struct ifreq ifr;
- struct timeval tv, last_tv;
+ struct timespec *stamp;
+ static struct timeval tv, last_tv;
struct timeval timeout, timeout_config = { 0, 0 }, *timeout_current = NULL;
FILE *logfile = NULL;
@@ -244,6 +250,7 @@ int main(int argc, char **argv)
case 't':
timestamp = optarg[0];
if ((timestamp != 'a') && (timestamp != 'A') &&
+ (timestamp != 'r') && (timestamp != 's') &&
(timestamp != 'd') && (timestamp != 'z')) {
fprintf(stderr, "%s: unknown timestamp mode '%c' - ignored\n",
basename(argv[0]), optarg[0]);
@@ -537,12 +544,30 @@ int main(int argc, char **argv)
if (timestamp || log || logfrmt) {
- const int timestamp_on = 1;
+ if ((timestamp != 'r') && (timestamp != 's')) {
- if (setsockopt(s[i], SOL_SOCKET, SO_TIMESTAMP,
- ×tamp_on, sizeof(timestamp_on)) < 0) {
- perror("setsockopt SO_TIMESTAMP");
- return 1;
+ const int timestamp_on = 1;
+
+ if (setsockopt(s[i], SOL_SOCKET, SO_TIMESTAMP,
+ ×tamp_on, sizeof(timestamp_on)) < 0) {
+ perror("setsockopt SO_TIMESTAMP");
+ return 1;
+ }
+ } else {
+
+// int timestamping_flags = (SOF_TIMESTAMPING_RX_SOFTWARE | SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_HARDWARE);
+ int timestamping_flags = (SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_HARDWARE);
+
+ if (timestamp == 'r')
+ timestamping_flags |= SOF_TIMESTAMPING_RAW_HARDWARE;
+ else
+ timestamping_flags |= SOF_TIMESTAMPING_SYS_HARDWARE;
+
+ if (setsockopt(s[i], SOL_SOCKET, SO_TIMESTAMPING,
+ ×tamping_flags, sizeof(timestamping_flags)) < 0) {
+ perror("setsockopt SO_TIMESTAMPING");
+ return 1;
+ }
}
}
@@ -600,7 +625,7 @@ int main(int argc, char **argv)
msg.msg_name = &addr;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
- msg.msg_control = &ctrlmsg;
+ msg.msg_control = &control;
while (running) {
@@ -626,7 +651,7 @@ int main(int argc, char **argv)
/* these settings may be modified by recvmsg() */
iov.iov_len = sizeof(frame);
msg.msg_namelen = sizeof(addr);
- msg.msg_controllen = sizeof(ctrlmsg);
+ msg.msg_controllen = sizeof(control);
msg.msg_flags = 0;
nbytes = recvmsg(s[i], &msg, 0);
@@ -664,10 +689,48 @@ int main(int argc, char **argv)
for (cmsg = CMSG_FIRSTHDR(&msg);
cmsg && (cmsg->cmsg_level == SOL_SOCKET);
cmsg = CMSG_NXTHDR(&msg,cmsg)) {
- if (cmsg->cmsg_type == SO_TIMESTAMP)
+
+ switch (cmsg->cmsg_type) {
+
+ case SO_TIMESTAMP:
+ printf("SO_TIMESTAMP\n");
tv = *(struct timeval *)CMSG_DATA(cmsg);
- else if (cmsg->cmsg_type == SO_RXQ_OVFL)
+ break;
+
+ case SO_TIMESTAMPING:
+ stamp = (struct timespec *)CMSG_DATA(cmsg);
+ printf("SO_TIMESTAMPING\n");
+
+ if (timestamp == 'r') {
+ tv.tv_sec = (stamp + 2)->tv_sec;
+ tv.tv_usec = (stamp + 2)->tv_nsec/1000;
+ } else {
+ tv.tv_sec = (stamp + 1)->tv_sec;
+ tv.tv_usec = (stamp + 1)->tv_nsec/1000;
+ }
+
+ printf("SW %lu.%09lu ",
+ (long)stamp->tv_sec,
+ (long)stamp->tv_nsec);
+ stamp++;
+ printf("HW transformed %lu.%09lu ",
+ (long)stamp->tv_sec,
+ (long)stamp->tv_nsec);
+ stamp++;
+ printf("HW raw %lu.%09lu",
+ (long)stamp->tv_sec,
+ (long)stamp->tv_nsec);
+ printf("\n");
+ break;
+
+ case SO_RXQ_OVFL:
+ printf("SO_RXQ_OVFL\n");
dropcnt[i] = *(__u32 *)CMSG_DATA(cmsg);
+ break;
+
+ default:
+ printf("unknown cmsg_type = %d\n", cmsg->cmsg_type);
+ }
}
/* check for (unlikely) dropped frames on this specific socket */
@@ -726,6 +789,8 @@ int main(int argc, char **argv)
switch (timestamp) {
case 'a': /* absolute with timestamp */
+ case 'r': /* absolute with raw hardware timestamp */
+ case 's': /* absolute with system hardware transformed timestamp */
printf("(%010ld.%06ld) ", tv.tv_sec, tv.tv_usec);
break;
diff --git a/include/linux/net_tstamp.h b/include/linux/net_tstamp.h
index e69de29..a8724a7 100644
--- a/include/linux/net_tstamp.h
+++ b/include/linux/net_tstamp.h
@@ -0,0 +1 @@
+#include <socketcan/net_tstamp.h>
diff --git a/include/socketcan/net_tstamp.h b/include/socketcan/net_tstamp.h
index e69de29..ae5df12 100644
--- a/include/socketcan/net_tstamp.h
+++ b/include/socketcan/net_tstamp.h
@@ -0,0 +1,113 @@
+/*
+ * Userspace API for hardware time stamping of network packets
+ *
+ * Copyright (C) 2008,2009 Intel Corporation
+ * Author: Patrick Ohly <patrick.ohly@intel.com>
+ *
+ */
+
+#ifndef _NET_TIMESTAMPING_H
+#define _NET_TIMESTAMPING_H
+
+#include <linux/socket.h> /* for SO_TIMESTAMPING */
+
+/* SO_TIMESTAMPING gets an integer bit field comprised of these values */
+enum {
+ SOF_TIMESTAMPING_TX_HARDWARE = (1<<0),
+ SOF_TIMESTAMPING_TX_SOFTWARE = (1<<1),
+ SOF_TIMESTAMPING_RX_HARDWARE = (1<<2),
+ SOF_TIMESTAMPING_RX_SOFTWARE = (1<<3),
+ SOF_TIMESTAMPING_SOFTWARE = (1<<4),
+ SOF_TIMESTAMPING_SYS_HARDWARE = (1<<5),
+ SOF_TIMESTAMPING_RAW_HARDWARE = (1<<6),
+ SOF_TIMESTAMPING_MASK =
+ (SOF_TIMESTAMPING_RAW_HARDWARE - 1) |
+ SOF_TIMESTAMPING_RAW_HARDWARE
+};
+
+/**
+ * struct hwtstamp_config - %SIOCSHWTSTAMP parameter
+ *
+ * @flags: no flags defined right now, must be zero
+ * @tx_type: one of HWTSTAMP_TX_*
+ * @rx_type: one of one of HWTSTAMP_FILTER_*
+ *
+ * %SIOCSHWTSTAMP expects a &struct ifreq with a ifr_data pointer to
+ * this structure. dev_ifsioc() in the kernel takes care of the
+ * translation between 32 bit userspace and 64 bit kernel. The
+ * structure is intentionally chosen so that it has the same layout on
+ * 32 and 64 bit systems, don't break this!
+ */
+struct hwtstamp_config {
+ int flags;
+ int tx_type;
+ int rx_filter;
+};
+
+/* possible values for hwtstamp_config->tx_type */
+enum hwtstamp_tx_types {
+ /*
+ * No outgoing packet will need hardware time stamping;
+ * should a packet arrive which asks for it, no hardware
+ * time stamping will be done.
+ */
+ HWTSTAMP_TX_OFF,
+
+ /*
+ * Enables hardware time stamping for outgoing packets;
+ * the sender of the packet decides which are to be
+ * time stamped by setting %SOF_TIMESTAMPING_TX_SOFTWARE
+ * before sending the packet.
+ */
+ HWTSTAMP_TX_ON,
+
+ /*
+ * Enables time stamping for outgoing packets just as
+ * HWTSTAMP_TX_ON does, but also enables time stamp insertion
+ * directly into Sync packets. In this case, transmitted Sync
+ * packets will not received a time stamp via the socket error
+ * queue.
+ */
+ HWTSTAMP_TX_ONESTEP_SYNC,
+};
+
+/* possible values for hwtstamp_config->rx_filter */
+enum hwtstamp_rx_filters {
+ /* time stamp no incoming packet at all */
+ HWTSTAMP_FILTER_NONE,
+
+ /* time stamp any incoming packet */
+ HWTSTAMP_FILTER_ALL,
+
+ /* return value: time stamp all packets requested plus some others */
+ HWTSTAMP_FILTER_SOME,
+
+ /* PTP v1, UDP, any kind of event packet */
+ HWTSTAMP_FILTER_PTP_V1_L4_EVENT,
+ /* PTP v1, UDP, Sync packet */
+ HWTSTAMP_FILTER_PTP_V1_L4_SYNC,
+ /* PTP v1, UDP, Delay_req packet */
+ HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ,
+ /* PTP v2, UDP, any kind of event packet */
+ HWTSTAMP_FILTER_PTP_V2_L4_EVENT,
+ /* PTP v2, UDP, Sync packet */
+ HWTSTAMP_FILTER_PTP_V2_L4_SYNC,
+ /* PTP v2, UDP, Delay_req packet */
+ HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ,
+
+ /* 802.AS1, Ethernet, any kind of event packet */
+ HWTSTAMP_FILTER_PTP_V2_L2_EVENT,
+ /* 802.AS1, Ethernet, Sync packet */
+ HWTSTAMP_FILTER_PTP_V2_L2_SYNC,
+ /* 802.AS1, Ethernet, Delay_req packet */
+ HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ,
+
+ /* PTP v2/802.AS1, any layer, any kind of event packet */
+ HWTSTAMP_FILTER_PTP_V2_EVENT,
+ /* PTP v2/802.AS1, any layer, Sync packet */
+ HWTSTAMP_FILTER_PTP_V2_SYNC,
+ /* PTP v2/802.AS1, any layer, Delay_req packet */
+ HWTSTAMP_FILTER_PTP_V2_DELAY_REQ,
+};
+
+#endif /* _NET_TIMESTAMPING_H */
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