1 files changed, 19 insertions, 32 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 9137b54613e0..1ab5e9d7fa50 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -145,18 +145,11 @@ void second_overflow(void)
         }
 
         /*
-         * Compute the phase adjustment for the next second. In PLL mode, the
-         * offset is reduced by a fixed factor times the time constant. In FLL
-         * mode the offset is used directly. In either mode, the maximum phase
-         * adjustment for each second is clamped so as to spread the adjustment
-         * over not more than the number of seconds between updates.
+         * Compute the phase adjustment for the next second. The offset is
+         * reduced by a fixed factor times the time constant.
          */
         tick_length = tick_length_base;
-        time_adj = time_offset;
-        if (!(time_status & STA_FLL))
-                time_adj = shift_right(time_adj, SHIFT_KG + time_constant);
-        time_adj = min(time_adj, -((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
-        time_adj = max(time_adj, ((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
+        time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
         time_offset -= time_adj;
         tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - SHIFT_UPDATE);
 
@@ -200,7 +193,7 @@ void __attribute__ ((weak)) notify_arch_cmos_timer(void)
 int do_adjtimex(struct timex *txc)
 {
         long ltemp, mtemp, save_adjust;
-        s64 freq_adj;
+        s64 freq_adj, temp64;
         int result;
 
         /* In order to modify anything, you gotta be super-user! */
@@ -270,7 +263,7 @@ int do_adjtimex(struct timex *txc)
                     result = -EINVAL;
                     goto leave;
                 }
-                time_constant = txc->constant;
+                time_constant = min(txc->constant + 4, (long)MAXTC);
             }
 
             if (txc->modes & ADJ_OFFSET) {      /* values checked earlier */
@@ -298,26 +291,20 @@ 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) {
-                            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) {
-                            freq_adj = (s64)ltemp * mtemp;
-                            freq_adj = shift_right(freq_adj,(time_constant +
-                                                       time_constant +
-                                                       SHIFT_KF - SHIFT_NSEC));
-                        } else /* calibration interval too long (p. 12) */
-                                result = TIME_ERROR;
+
+                    freq_adj = (s64)time_offset * mtemp;
+                    freq_adj = shift_right(freq_adj, time_constant * 2 +
+                                           (SHIFT_PLL + 2) * 2 - SHIFT_NSEC);
+                    if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
+                        temp64 = (s64)time_offset << (SHIFT_NSEC - SHIFT_FLL);
+                        if (time_offset < 0) {
+                            temp64 = -temp64;
+                            do_div(temp64, mtemp);
+                            freq_adj -= temp64;
+                        } else {
+                            do_div(temp64, mtemp);
+                            freq_adj += temp64;
+                        }
                     }
                     freq_adj += time_freq;
                     freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);