Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ntp: Clamp PLL update interval
+11
-3
kernel/time/ntp.c
+11
-3
kernel/time/ntp.c
···
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time_reftime = get_seconds();
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offset64 = offset;
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-
freq_adj = (offset64 * secs) <<
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-
(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
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+
freq_adj = ntp_update_offset_fll(offset64, secs);
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-
freq_adj += ntp_update_offset_fll(offset64, secs);
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+
/*
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* Clamp update interval to reduce PLL gain with low
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+
* sampling rate (e.g. intermittent network connection)
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* to avoid instability.
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*/
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+
if (unlikely(secs > 1 << (SHIFT_PLL + 1 + time_constant)))
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secs = 1 << (SHIFT_PLL + 1 + time_constant);
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+
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freq_adj += (offset64 * secs) <<
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(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
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freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED);
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