Date: Thu, 28 Oct 1999 02:11:44 +0900 From: Mitsuru IWASAKI <iwasaki@jp.FreeBSD.org> To: mike@smith.net.au Cc: iwasaki@jp.FreeBSD.org, steveo@iol.ie, freebsd-mobile@freebsd.org, cvs-committers@freebsd.org Subject: Re: FreeBSD on a Compaq 1690 Message-ID: <199910271711.CAA28493@tasogare.imasy.or.jp> In-Reply-To: Your message of "Wed, 27 Oct 1999 09:49:03 -0700" <199910271649.JAA03917@dingo.cdrom.com> References: <199910271649.JAA03917@dingo.cdrom.com>
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Hi,
> > Linux people also are doing also reloading the countdown register of
> > i8254 after suspend in the same way. It couldn't hurt, I think.
> >
> > #ifdef INIT_TIMER_AFTER_SUSPEND
>
> ...
>
> Don't make it conditional on yet another obscure define. It should be
> the default behaviour.
Sure, I think so too. My previous mail showed the equivalent code in
linux kernel :-)
The patch I'm going to commit is following.
Index: sys/i386/apm/apm.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/apm/apm.c,v
retrieving revision 1.77.2.13
diff -u -r1.77.2.13 apm.c
--- apm.c 1999/10/13 22:06:46 1.77.2.13
+++ apm.c 1999/10/23 21:03:17
@@ -450,6 +450,7 @@
/* modified for adjkerntz */
pl = splsoftclock();
+ i8254_restore(); /* restore timer_freq and hz */
inittodr(0); /* adjust time to RTC */
microtime(&resume_time);
getmicrotime(&tmp_time);
Index: sys/i386/include/clock.h
===================================================================
RCS file: /home/ncvs/src/sys/i386/include/clock.h,v
retrieving revision 1.34.2.2
diff -u -r1.34.2.2 clock.h
--- clock.h 1999/08/29 16:06:23 1.34.2.2
+++ clock.h 1999/10/23 21:02:24
@@ -44,6 +44,7 @@
int release_timer1 __P((void));
#endif
int sysbeep __P((int pitch, int period));
+void i8254_restore __P((void));
#endif /* KERNEL */
Index: sys/i386/isa/clock.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/isa/clock.c,v
retrieving revision 1.129.2.4
diff -u -r1.129.2.4 clock.c
--- clock.c 1999/08/29 16:07:14 1.129.2.4
+++ clock.c 1999/10/23 21:20:18
@@ -703,6 +703,28 @@
}
/*
+ * i8254_restore is called from apm_default_resume() to reload
+ * the countdown register.
+ * this should not be necessary but there are broken laptops that
+ * do not restore the countdown register on resume.
+ * when it happnes, it messes up the hardclock interval and system clock,
+ * which leads to the infamous "calcru: negative time" problem.
+ */
+void
+i8254_restore(void)
+{
+ u_long ef;
+
+ ef = read_eflags();
+ disable_intr();
+ outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
+ outb(TIMER_CNTR0, timer0_max_count & 0xff);
+ outb(TIMER_CNTR0, timer0_max_count >> 8);
+ CLOCK_UNLOCK();
+ write_eflags(ef);
+}
+
+/*
* Initialize 8254 timer 0 early so that it can be used in DELAY().
* XXX initialization of other timers is unintentionally left blank.
*/
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