Re: rtc again...

On Thu, 3 Aug 2000, Gabriel Paubert wrote:

On Thu, 3 Aug 2000, Benjamin Herrenschmidt wrote:

quoted

quoted

I am using it as module both for 2.2.17-bk and for 2.4.0-test5. They
don't give the same time, and I think it is the one in 2.4.0 that is
right. I am at GMT+2:00, and the time in 2.2.17 is 2 hours early. When I
change /etc/sysconfig/clock from "UTC=false" to "UTC=true", both times
shift by 2 hours, but the discrepancy remains.

The following patch for bitkeeper linuxppc_2_2 fixes this problem for
me. It brings 2.2.17pre13 in line with 2.4.0-test5 (and MacOS). I cannot
test the VIAPMU part, so maybe there the offset is necessary, but for
the VIACUDA part, it seems wrong.

You patch reverts a fix I made some time ago. Basially, what probably
happens is that your RTC is in UTC time, not in local time. The Mac RTC
is supposed to be in local time, the offset corrects the kernel time on
boot to account for this. Previously, without that fix, the kernel used
to boot with a bogus UTC time until userland fixes it.

Actually given the problems with RTC being UTC or local time, the offset
might perhaps better be setup as a kernel parameter so that th system
start up in a known good state. It seems that it is in RAM for Macs, but
what about other machines (I have no problems since all my machines are
UTC and I simply refuse to use an OS which requires anything else) ?

Why do you want to handle the offset in the kernel???

Any decent distro (e.g. Debian) allows to configure the time system for a
hardware clock running in either UTC or local time, so the correction will be
done on boot up.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds


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