Date: Fri, 9 Mar 2001 00:43:19 -0800 (PST) From: Matthew Jacob <mjacob@feral.com> To: Yoriaki FUJIMORI <fujimori@baron.fujimori.cache.waseda.ac.jp> Cc: freebsd-alpha@freebsd.org, Jordan Hubbard <jkh@bsdi.com> Subject: realtime clock problem solved Message-ID: <Pine.BSF.4.21.0103090040070.4175-100000@beppo.feral.com> In-Reply-To: <200103051823.f25INdT38459@baron.fujimori.cache.waseda.ac.jp>
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On Mon, 5 Mar 2001, Yoriaki FUJIMORI wrote:
>
> As for a realtime clock problem, it should persist on many alphapc164,
> pc164lx and up1100. At least in my lab, they all suffer from this.
> It was a fun to see `Feb 29, 2000' on all of them. (;_;)
>
> I guess FreeBSD/Alpha alone makes use of mcclock.c. I could not find
> its counterpart in FreeBSD/i386.
>
> Yoriaki Fujimori
>
I think I have a fix for this- it fixed my problem. The problem here is that
the clock register was being written with a > 2 digit value. The below patch
could be simpler in that just the update of the regs value should come after
the rolloff to 2 digits.
Could you try this for your machines?
Jordan? If this pans out is this still possible to get into 4.3?
Index: sys/dev/dec/mcclock.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/dec/mcclock.c,v
retrieving revision 1.5
diff -u -r1.5 mcclock.c
--- sys/dev/dec/mcclock.c 2000/01/04 03:22:04 1.5
+++ sys/dev/dec/mcclock.c 2001/03/09 08:39:19
@@ -84,10 +84,7 @@
ct->day = regs[MC_DOM];
ct->mon = regs[MC_MONTH];
ct->year = regs[MC_YEAR];
- /*
- * This chip is not y2k compliant, so we'll do a 10 year window fix.
- */
- if (ct->year >= 0 && ct->year < 10) {
+ if (ct->year < 70) {
ct->year += 100;
}
}
@@ -111,15 +108,7 @@
regs[MC_DOW] = ct->dow;
regs[MC_DOM] = ct->day;
regs[MC_MONTH] = ct->mon;
- regs[MC_YEAR] = ct->year;
- /*
- * This chip is not y2k compliant, so we'll do a 10 year window fix.
- * It's probably okay to write more than 100, but let's not and
- * and say we didn't.
- */
- if (ct->year >= 100) {
- ct->year -= 100;
- }
+ regs[MC_YEAR] = ct->year % 100;
s = splclock();
MC146818_PUTTOD(dev, ®s);
splx(s);
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