.TH HWSTAMP_CTL 8 "June 2014" "linuxptp"

.SH NAME

hwstamp_ctl \- set time stamping policy at the driver level

.SH SYNOPSIS

.B hwstamp_ctl

.BI \-i " interface"

[

.BI \-r " rx-filter"

] [

.BI \-t " tx-type"

] [

.B \-v

]

.SH DESCRIPTION

.B hwstamp_ctl

is a program used to set and get the hardware time stamping policy at the network

driver level with the

.B SIOCSHWTSTAMP

.BR ioctl (2).

The

.I tx-type

and

.I rx-filter

values are hints to the driver what it is expected to do. If the requested

fine-grained filtering for incoming packets is not supported, the driver may

time stamp more than just the requested types of packets.

If neither

.I tx-type

nor

.I rx-filter

values are passed to the program, it will use the

.B SIOCGHWTSTAMP

.BR ioctl(2)

to non-destructively read the current hardware time stamping policy.

This program is a debugging tool. The

.BR ptp4l (8)

program does not need this program to function, it will set the policy

automatically as appropriate.

.SH OPTIONS

.TP

.BI \-i " interface"

Specify the network interface of which the policy should be changed.

.TP

.BI \-r " rx-filter"

Specify which types of incoming packets should be time stamped,

.I rx-filter

is an integer value.

.TP

.BI \-t " tx-type"

Enable or disable hardware time stamping for outgoing packets,

.I tx-type

is an integer value.

.TP

.BI \-h

Display a help message and list of possible values for

.I rx-filter

and

.IR tx-type .

.TP

.B \-v

Prints the software version and exits.

.SH SEE ALSO

.BR ioctl (2),

.BR ptp4l (8)