This servo uses linear regression to estimate current time and
frequency error. The number of points used in the regression is
variable (from 4 to 64 in powers of 2) and is selected by a long-term
statistic of the prediction error.
Future improvements could include tracking of sudden frequency changes
(e.g. due to temperature variations), better stability of the error
statistic when a large offset is corrected, options to set the speed of
the adaptation, minimum and maximum number of points, or an option to
prefer frequency accuracy over time accuracy.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Median filter has an advantage over moving average that it is much less
sensitive to outliers.
For instance, it allows much faster recovery from an external clock
time step which happened between receiving sync message and sending
delay_req message. The measured delay includes a large error, but the
median is still a good estimate of the delay and the first step
correction applied by the servo is right.
In this implementation the median update has linear time complexity.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Similarly to the servo interface, allow multiple filters to be
used for delay filtering. Convert mave to the new interface.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Instead of maintaining a table of precalculated values, use the
newly added set_tmo_random() function to set the delay request timeout.
It saves some memory and improves the timeout granularity, but has a
higher computational cost. It follows the requirements from section
9.5.11.2 of the spec.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Check the sanity of the synchronized clock by comparing its uncorrected
frequency with the system monotonic clock. When the measured frequency
offset is larger than the value of the sanity_freq_limit option (20% by
default), a warning message will be printed and the servo will be reset.
Setting the option to zero disables the check.
This is useful to detect when the clock is broken or adjusted by another
program.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
This patch introduces a shell script to figure out the proper definitions
for the HAVE_CLOCK_ADJTIME and HAVE_ONESTEP_SYNC macros, as well as the
include path. The intent is to "do the right thing" for three different
user scenarios, namely cross compiling, compiling against a custom kernel,
and using a plain old disto kernel.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
this patch uses grep to test whether the net_tstamp.h header has
HWTSTAMP_TX_ONESTEP_SYNC flag defined. If it doesn't then we can simply define
it with the correct value. This works because proper drivers should just report
that the value is not allowed if they don't support onestep mode. This is the
cleanest way to ensure that linuxptp will still work on kernels which have not
defined the one step flag, and also works for any distributions which backport
the feature.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Ever since upgrading to Debian 7.0, building linuxptp results in an
annoying error message. This is due to the fact that the directory
/usr/include/bits is no longer present, but our makefile expects it
to exist. This patch fixes the issue by telling grep not to complain
about missing files.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Add new options to ptp4l and phc2sys to print summary statistics of the
clock instead of the individual samples.
[ RC - Fix () function prototype with (void).
- Use unsigned for sample counter.
- Fix over-zealous line breaks. ]
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Add a new option to wait for ptp4l to be in a synchronized state.
Periodically check PORT_DATA_SET and wait until there is a port in
SLAVE, MASTER or GRAND_MASTER state. Also, set the default
synchronization offset according to the currentUtcOffset value from
TIME_PROPERTIES_DATA_SET and the direction of the clock synchronization.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
We use the PTP_SYS_OFFSET ioctl method in preference to doing
clock_gettime from user space, the assumption being that the kernel space
measurement will always be more accurate.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
This patch adds support for sk_interface_phc to lookup the /dev/ptpX device
using ethtool's get_ts_info ioctl
-v2-
* set ethdev to null initially
* rebased on top of phc2sys changes
-v3-
* fixed typo regarding slash
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
This is really just a first attempt using a hard coded length. Probably
it will be necessary to let the length be configurable and/or adaptable.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
We can pre-compute a table of suitable values in order to simplify the
run time random delay selection.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Since the master implementation is still lacking, we will just keep
the slave-only flag hard coded for now.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
This commit also introduces clock and port objects, but only with the
minimal interface needed by the BMC.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Miroslav Lichvar
Richard Cochran
Jacob Keller
Delio Brignoli