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-rw-r--r--kernel/timer.c53
1 files changed, 11 insertions, 42 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index 6ed1a826e5ce..6b94adb45b03 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -703,23 +703,13 @@ static void second_overflow(void)
703 * the adjustment over not more than the number of 703 * the adjustment over not more than the number of
704 * seconds between updates. 704 * seconds between updates.
705 */ 705 */
706 if (time_offset < 0) {
707 ltemp = -time_offset;
708 if (!(time_status & STA_FLL))
709 ltemp >>= SHIFT_KG + time_constant;
710 if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
711 ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
712 time_offset += ltemp;
713 time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
714 } else {
715 ltemp = time_offset; 706 ltemp = time_offset;
716 if (!(time_status & STA_FLL)) 707 if (!(time_status & STA_FLL))
717 ltemp >>= SHIFT_KG + time_constant; 708 ltemp = shift_right(ltemp, SHIFT_KG + time_constant);
718 if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE) 709 ltemp = min(ltemp, (MAXPHASE / MINSEC) << SHIFT_UPDATE);
719 ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE; 710 ltemp = max(ltemp, -(MAXPHASE / MINSEC) << SHIFT_UPDATE);
720 time_offset -= ltemp; 711 time_offset -= ltemp;
721 time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); 712 time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
722 }
723 713
724 /* 714 /*
725 * Compute the frequency estimate and additional phase 715 * Compute the frequency estimate and additional phase
@@ -736,39 +726,25 @@ static void second_overflow(void)
736 STA_PPSWANDER | STA_PPSERROR); 726 STA_PPSWANDER | STA_PPSERROR);
737 } 727 }
738 ltemp = time_freq + pps_freq; 728 ltemp = time_freq + pps_freq;
739 if (ltemp < 0) 729 time_adj += shift_right(ltemp,(SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE));
740 time_adj -= -ltemp >>
741 (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
742 else
743 time_adj += ltemp >>
744 (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
745 730
746#if HZ == 100 731#if HZ == 100
747 /* Compensate for (HZ==100) != (1 << SHIFT_HZ). 732 /* Compensate for (HZ==100) != (1 << SHIFT_HZ).
748 * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14) 733 * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14)
749 */ 734 */
750 if (time_adj < 0) 735 time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5);
751 time_adj -= (-time_adj >> 2) + (-time_adj >> 5);
752 else
753 time_adj += (time_adj >> 2) + (time_adj >> 5);
754#endif 736#endif
755#if HZ == 250 737#if HZ == 250
756 /* Compensate for (HZ==250) != (1 << SHIFT_HZ). 738 /* Compensate for (HZ==250) != (1 << SHIFT_HZ).
757 * Add 1.5625% and 0.78125% to get 255.85938; => only 0.05% error (p. 14) 739 * Add 1.5625% and 0.78125% to get 255.85938; => only 0.05% error (p. 14)
758 */ 740 */
759 if (time_adj < 0) 741 time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
760 time_adj -= (-time_adj >> 6) + (-time_adj >> 7);
761 else
762 time_adj += (time_adj >> 6) + (time_adj >> 7);
763#endif 742#endif
764#if HZ == 1000 743#if HZ == 1000
765 /* Compensate for (HZ==1000) != (1 << SHIFT_HZ). 744 /* Compensate for (HZ==1000) != (1 << SHIFT_HZ).
766 * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14) 745 * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14)
767 */ 746 */
768 if (time_adj < 0) 747 time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
769 time_adj -= (-time_adj >> 6) + (-time_adj >> 7);
770 else
771 time_adj += (time_adj >> 6) + (time_adj >> 7);
772#endif 748#endif
773} 749}
774 750
@@ -787,10 +763,8 @@ static void update_wall_time_one_tick(void)
787 * Limit the amount of the step to be in the range 763 * Limit the amount of the step to be in the range
788 * -tickadj .. +tickadj 764 * -tickadj .. +tickadj
789 */ 765 */
790 if (time_adjust > tickadj) 766 time_adjust_step = min(time_adjust_step, (long)tickadj);
791 time_adjust_step = tickadj; 767 time_adjust_step = max(time_adjust_step, (long)-tickadj);
792 else if (time_adjust < -tickadj)
793 time_adjust_step = -tickadj;
794 768
795 /* Reduce by this step the amount of time left */ 769 /* Reduce by this step the amount of time left */
796 time_adjust -= time_adjust_step; 770 time_adjust -= time_adjust_step;
@@ -801,13 +775,8 @@ static void update_wall_time_one_tick(void)
801 * advance the tick more. 775 * advance the tick more.
802 */ 776 */
803 time_phase += time_adj; 777 time_phase += time_adj;
804 if (time_phase <= -FINENSEC) { 778 if ((time_phase >= FINENSEC) || (time_phase <= -FINENSEC)) {
805 long ltemp = -time_phase >> (SHIFT_SCALE - 10); 779 long ltemp = shift_right(time_phase, (SHIFT_SCALE - 10));
806 time_phase += ltemp << (SHIFT_SCALE - 10);
807 delta_nsec -= ltemp;
808 }
809 else if (time_phase >= FINENSEC) {
810 long ltemp = time_phase >> (SHIFT_SCALE - 10);
811 time_phase -= ltemp << (SHIFT_SCALE - 10); 780 time_phase -= ltemp << (SHIFT_SCALE - 10);
812 delta_nsec += ltemp; 781 delta_nsec += ltemp;
813 } 782 }