[src/trunk]: src/sys/arch/arm/samsung Fix missed clock interrupts calculation

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/afec061386ee
branches:  trunk
changeset: 798081:afec061386ee
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Fri Aug 08 14:43:14 2014 +0000

description:
Fix missed clock interrupts calculation

diffstat:

 sys/arch/arm/samsung/mct.c |  19 +++++++++++--------
 1 files changed, 11 insertions(+), 8 deletions(-)

diffs (49 lines):

diff -r 28cc24d948c1 -r afec061386ee sys/arch/arm/samsung/mct.c
--- a/sys/arch/arm/samsung/mct.c        Fri Aug 08 14:42:58 2014 +0000
+++ b/sys/arch/arm/samsung/mct.c        Fri Aug 08 14:43:14 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mct.c,v 1.2 2014/05/09 22:21:46 reinoud Exp $  */
+/*     $NetBSD: mct.c,v 1.3 2014/08/08 14:43:14 reinoud Exp $  */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(1, "$NetBSD: mct.c,v 1.2 2014/05/09 22:21:46 reinoud Exp $");
+__KERNEL_RCSID(1, "$NetBSD: mct.c,v 1.3 2014/08/08 14:43:14 reinoud Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -230,21 +230,24 @@
        struct clockframe * const cf = arg;
        struct mct_softc * const sc = &mct_sc;
        const uint64_t now = mct_gettime(sc);
-       uint64_t delta = now - sc->sc_lastintr;
-       uint64_t missed = delta / sc->sc_autoinc;
+       int64_t delta = now - sc->sc_lastintr;
+       int64_t periods = delta / sc->sc_autoinc;
+
+       KASSERT(delta >= 0);
+       KASSERT(periods >= 0);
 
        /* ack the interrupt */
        mct_write_global(sc, MCT_G_INT_CSTAT, G_INT_CSTAT_CLEAR);
 
-       /* check if we missed clock interrupts */
-       if (delta > sc->sc_autoinc)
-               sc->sc_ev_missing_ticks.ev_count += missed;
+       /* check if we periods clock interrupts */
+       if (periods > 1)
+               sc->sc_ev_missing_ticks.ev_count += periods - 1;
 
        sc->sc_lastintr = now;
        hardclock(cf);
 
        if (sc->sc_has_blink_led) {
-               sc->sc_led_timer = sc->sc_led_timer - 1 - missed;
+               sc->sc_led_timer = sc->sc_led_timer - periods - 1;
                if (sc->sc_led_timer <= 0) {
                        sc->sc_led_state = !sc->sc_led_state;
                        exynos_gpio_pindata_write(&sc->sc_gpio_led,