From 1065f286b4bcae288f560fad37e37363eed58d34 Mon Sep 17 00:00:00 2001 From: Alessandro Rubini <rubini@gnudd.com> Date: Wed, 3 Dec 2014 15:54:15 +0100 Subject: [PATCH] doc: documented new clocksource module Signed-off-by: Alessandro Rubini <rubini@gnudd.com> --- doc/wrs-developer-manual.in | 9 +++++++++ doc/wrs-todo.in | 10 ---------- 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/doc/wrs-developer-manual.in b/doc/wrs-developer-manual.in index a8f3004f5..6ca9947ff 100644 --- a/doc/wrs-developer-manual.in +++ b/doc/wrs-developer-manual.in @@ -748,6 +748,15 @@ Currently, the package includes the following modules: @item @i{wr_rtu.ko}: the routing-table interface between the switching core and the associated user-space daemon. @item @i{wr_pstats.ko}: exports per-port statistics to /proc/sys. + +@item @i{wr_clocksource.ko}: uses WR time as a source for system time. +This driver uses the @sc{wr} counters to make host time flow at the +right speed. The system time is moved to the current value, with an +error not bigger than one second, as soon as @i{ppsi} synchronizes, +and the clocksource grants it won't move ever after, keeping the same +offset. This is considered acceptable, because system time is only +used for logging. + @item @i{at91_softpwm.ko}: a driver that generates a PWM signal for the fan. @end itemize diff --git a/doc/wrs-todo.in b/doc/wrs-todo.in index 8dac17403..2a367738f 100644 --- a/doc/wrs-todo.in +++ b/doc/wrs-todo.in @@ -159,16 +159,6 @@ like increasing @t{NR_IRQ} and exporting symbols for externally-loaded the counters are. This would make the @sc{snmp} code generic, so no change there would be needed if and when the counters change. -@item We need RTC driver to use WR time from FPGA as a system clock in Linux -running on WR Switch (or to synchronize the system clock). Setting initial time -from NTP is good for Grand Master in the network, but then we should keep all -system clocks in sync with WR timescale. It will become important when people -start gathering logs and SNMP info on a central server and would like to -correlate logs if something bad happens. Let's keep in mind that currently -unplugging fiber from the Slave port resets WR counters (i.e. current time -00:00 01/01/1970). System clock should not follow this, we need to keep -reporting failures timestamped with correct time. - @end itemize @c ########################################################################## -- GitLab