On 21 February 2011 09:45, Karel Zak <kzak@xxxxxxxxxx> wrote:
> The problem is backward compatibility. People who depend on the
> current hwclock default will hate us :-)
There will be some impact, but I don't think it will be significant.
Anyone who has run hwclock at some time in the past will already have
their choice of UTC or LOCAL stored in /etc/adjtime, so changing the
default won't affect them.
I've attached a patch which switches hwclock's default to UTC without
any backwards-compat considerations, but if you still feel uneasy, let
me know and I'll produce a configure-based one instead.
Thanks,
Daniel
From a09091f19c38a82b9a39b43ebded1f9c66fabea4 Mon Sep 17 00:00:00 2001
From: Daniel Drake <dsd@xxxxxxxxxx>
Date: Mon, 21 Feb 2011 13:27:07 +0000
Subject: [PATCH] hwclock: make RTC default to UTC time
If /etc/adjtime doesn't specify UTC or LOCAL, rtcwake defaults to UTC
and hwclock defaults to LOCAL.
Switch hwclock to meet the behaviour of rtcwake (default=UTC), also
matching the kernel's CONFIG_RTC_HCTOSYS behaviour.
The user impact of this change should be minimal, as anyone who has run
"hwclock --systohc" before will have their UTC/LOCAL choice already
recorded in /etc/adjtime.
Signed-off-by: Daniel Drake <dsd@xxxxxxxxxx>
---
hwclock/hwclock.8 | 2 +-
hwclock/hwclock.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/hwclock/hwclock.8 b/hwclock/hwclock.8
index 31f7692..b693ae2 100644
--- a/hwclock/hwclock.8
+++ b/hwclock/hwclock.8
@@ -169,7 +169,7 @@ was used to set the clock (i.e. hwclock was successfully run with the
or
.B \-\-adjust
options), as recorded in the adjtime file. If the adjtime file doesn't
-exist, the default is local time.
+exist, the default is UTC time.
.TP
.B \-\-noadjfile
diff --git a/hwclock/hwclock.c b/hwclock/hwclock.c
index 279b672..88fb8a0 100644
--- a/hwclock/hwclock.c
+++ b/hwclock/hwclock.c
@@ -224,8 +224,8 @@ hw_clock_is_utc(const bool utc, const bool local_opt,
else if (local_opt)
ret = FALSE; /* --localtime explicitly given */
else
- /* get info from adjtime file - default is local */
- ret = (adjtime.local_utc == UTC);
+ /* get info from adjtime file - default is UTC */
+ ret = (adjtime.local_utc != LOCAL);
if (debug)
printf(_("Assuming hardware clock is kept in %s time.\n"),
ret ? _("UTC") : _("local"));
--
1.7.4
