diff options
| -rw-r--r-- | include/linux/timex.h | 2 | ||||
| -rw-r--r-- | kernel/time/ntp.c | 36 |
2 files changed, 24 insertions, 14 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h index 7715b4c0caf..671609ee1a3 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -91,10 +91,12 @@ #define SHIFT_SCALE 22 /* phase scale (shift) */ #define SHIFT_UPDATE (SHIFT_HZ + 1) /* time offset scale (shift) */ #define SHIFT_USEC 16 /* frequency offset scale (shift) */ +#define SHIFT_NSEC 12 /* kernel frequency offset scale */ #define FINENSEC (1L << (SHIFT_SCALE - 10)) /* ~1 ns in phase units */ #define MAXPHASE 512000L /* max phase error (us) */ #define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */ +#define MAXFREQ_NSEC (512000L << SHIFT_NSEC) /* max frequency error (ppb) */ #define MINSEC 16L /* min interval between updates (s) */ #define MAXSEC 1200L /* max interval between updates (s) */ #define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */ diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index af7563f5d4e..9137b54613e 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -66,7 +66,7 @@ void ntp_update_frequency(void) { tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT; tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT; - tick_length_base += ((s64)time_freq * NSEC_PER_USEC) << (TICK_LENGTH_SHIFT - SHIFT_USEC); + tick_length_base += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC); do_div(tick_length_base, HZ); @@ -200,6 +200,7 @@ void __attribute__ ((weak)) notify_arch_cmos_timer(void) int do_adjtimex(struct timex *txc) { long ltemp, mtemp, save_adjust; + s64 freq_adj; int result; /* In order to modify anything, you gotta be super-user! */ @@ -245,7 +246,7 @@ int do_adjtimex(struct timex *txc) result = -EINVAL; goto leave; } - time_freq = txc->freq; + time_freq = ((s64)txc->freq * NSEC_PER_USEC) >> (SHIFT_USEC - SHIFT_NSEC); } if (txc->modes & ADJ_MAXERROR) { @@ -278,14 +279,14 @@ int do_adjtimex(struct timex *txc) time_adjust = txc->offset; } else if (time_status & STA_PLL) { - ltemp = txc->offset; + ltemp = txc->offset * NSEC_PER_USEC; /* * Scale the phase adjustment and * clamp to the operating range. */ - time_offset = min(ltemp, MAXPHASE); - time_offset = max(time_offset, -MAXPHASE); + time_offset = min(ltemp, MAXPHASE * NSEC_PER_USEC); + time_offset = max(time_offset, -MAXPHASE * NSEC_PER_USEC); /* * Select whether the frequency is to be controlled @@ -297,24 +298,31 @@ int do_adjtimex(struct timex *txc) time_reftime = xtime.tv_sec; mtemp = xtime.tv_sec - time_reftime; time_reftime = xtime.tv_sec; + freq_adj = 0; if (time_status & STA_FLL) { if (mtemp >= MINSEC) { - ltemp = ((time_offset << 12) / mtemp) << (SHIFT_USEC - 12); - time_freq += shift_right(ltemp, SHIFT_KH); + freq_adj = (s64)time_offset << (SHIFT_NSEC - SHIFT_KH); + if (time_offset < 0) { + freq_adj = -freq_adj; + do_div(freq_adj, mtemp); + freq_adj = -freq_adj; + } else + do_div(freq_adj, mtemp); } else /* calibration interval too short (p. 12) */ result = TIME_ERROR; } else { /* PLL mode */ if (mtemp < MAXSEC) { - ltemp *= mtemp; - time_freq += shift_right(ltemp,(time_constant + + freq_adj = (s64)ltemp * mtemp; + freq_adj = shift_right(freq_adj,(time_constant + time_constant + - SHIFT_KF - SHIFT_USEC)); + SHIFT_KF - SHIFT_NSEC)); } else /* calibration interval too long (p. 12) */ result = TIME_ERROR; } - time_freq = min(time_freq, MAXFREQ); - time_freq = max(time_freq, -MAXFREQ); - time_offset = (time_offset * NSEC_PER_USEC / HZ) << SHIFT_UPDATE; + freq_adj += time_freq; + freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC); + time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC); + time_offset = (time_offset / HZ) << SHIFT_UPDATE; } /* STA_PLL */ } /* txc->modes & ADJ_OFFSET */ if (txc->modes & ADJ_TICK) @@ -330,7 +338,7 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0) txc->offset = save_adjust; else txc->offset = shift_right(time_offset, SHIFT_UPDATE) * HZ / 1000; - txc->freq = time_freq; + txc->freq = (time_freq / NSEC_PER_USEC) << (SHIFT_USEC - SHIFT_NSEC); txc->maxerror = time_maxerror; txc->esterror = time_esterror; txc->status = time_status; |