From ac1bb1ef9350a79a016d504022c710336244a112 Mon Sep 17 00:00:00 2001 From: Kalev Soikonen Date: Mon, 28 Jul 2008 02:26:44 +0300 Subject: [PATCH] hwclock: delay loop in set_hardware_clock_exact - Avoid delaying 1.5 seconds when 0.5 will do. - Guard for forward time resets as well. [kzak@redhat.com: - fix the "Delaying.." debug message - add comments] Signed-off-by: Kalev Soikonen Signed-off-by: Karel Zak --- hwclock/hwclock.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/hwclock/hwclock.c b/hwclock/hwclock.c index c08ae3f5..48b47ade 100644 --- a/hwclock/hwclock.c +++ b/hwclock/hwclock.c @@ -526,28 +526,32 @@ set_hardware_clock_exact(const time_t sethwtime, time_t newhwtime; struct timeval beginsystime, nowsystime; + double tdiff; time_resync: gettimeofday(&beginsystime, NULL); - newhwtime = sethwtime + (int) time_diff(beginsystime, refsystime) + 1; + tdiff = time_diff(beginsystime, refsystime); + newhwtime = sethwtime + (int) (tdiff + 0.5); if (debug) printf(_("Time elapsed since reference time has been %.6f seconds.\n" - "Delaying further to reach the next full second.\n"), - time_diff(beginsystime, refsystime)); + "Delaying further to reach the new time.\n"), tdiff); /* - * Now delay some more until Hardware Clock time newhwtime arrives. The -500 - * ms is because the Hardware Clock always sets to your set time plus 500 ms + * Now delay some more until Hardware Clock time newhwtime arrives. The 0.5 s + * is because the Hardware Clock always sets to your set time plus 500 ms * (because it is designed to update to the next second precisely 500 ms * after you finish the setting). */ do { - float tdiff; gettimeofday(&nowsystime, NULL); tdiff = time_diff(nowsystime, beginsystime); if (tdiff < 0) - goto time_resync; /* probably time was reset */ - } while (time_diff(nowsystime, refsystime) - 0.5 < newhwtime - sethwtime); + goto time_resync; /* probably backward time reset */ + if (tdiff > 0.1) + goto time_resync; /* probably forward time reset */ + beginsystime = nowsystime; + tdiff = time_diff(nowsystime, refsystime); + } while (newhwtime == sethwtime + (int) (tdiff + 0.5)); set_hardware_clock(newhwtime, universal, testing); } -- 2.39.5