On Sun, 2013-12-01 at 21:09 +0100, Richard Cochran wrote:
> According to 802.1AS, ports are always expected to transmit announce
> messages, even if they never want to become the grand master. Instead
> of using a slave only BMC state machine as in 1588, 802.1AS offers a
> "grand master capable" flag which allows clocks to not send sync
> messages.
>
> This patch keeps a port from transmitting sync (but not announce)
> messages when there is no other master.
>
> Signed-off-by: Richard Cochran <[email protected]>
> ---
> port.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/port.c b/port.c
> index 13a34a2..df94e8c 100644
> --- a/port.c
> +++ b/port.c
> @@ -532,6 +532,31 @@ static int port_ignore(struct port *p, struct
> ptp_message *m)
> return 0;
> }
>
> +/*
> + * Test whether a 802.1AS port may transmit a sync message.
> + */
> +static int port_incapable(struct port *p)
> +{
> + struct ClockIdentity cid;
> + struct PortIdentity pid;
> +
> + if (!port_is_ieee8021as(p)) {
> + return 0;
> + }
> + if (clock_gm_capable(p->clock)) {
> + return 0;
> + }
> + cid = clock_identity(p->clock);
> + pid = clock_parent_identity(p->clock);
> + if (!memcmp(&cid, &pid.clockIdentity, sizeof(cid))) {
> + /*
> + * We are the GM, but without gmCapable set.
> + */
> + return 1;
> + }
> + return 0;
> +}
> +
> static int port_is_ieee8021as(struct port *p)
> {
> return p->pod.follow_up_info ? 1 : 0;
> @@ -1148,6 +1173,9 @@ static int port_tx_sync(struct port *p)
> if (!port_capable(p)) {
> return 0;
> }
Is there a specific reason that port_capable and port_incapable are not
the same function?
Regards,
Jake
> + if (port_incapable(p)) {
> + return 0;
> + }
> msg = msg_allocate();
> if (!msg)
> return -1;
------------------------------------------------------------------------------
Rapidly troubleshoot problems before they affect your business. Most IT
organizations don't have a clear picture of how application performance
affects their revenue. With AppDynamics, you get 100% visibility into your
Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro!
http://pubads.g.doubleclick.net/gampad/clk?id=84349351&iu=/4140/ostg.clktrk
_______________________________________________
Linuxptp-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
