Merge "timekeeping: Cap adjustments so they don't exceed the maxadj value" (70be7025) · Commits · e / devices / android_kernel_sony_msm8998

kernel/time/timekeeping.c

+27 −4

Original line number	Diff line number	Diff line
		@@ -1669,9 +1669,12 @@ static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
		{
		s64 interval = tk->cycle_interval;
		s64 xinterval = tk->xtime_interval;
		u32 base = tk->tkr_mono.clock->mult;
		u32 max = tk->tkr_mono.clock->maxadj;
		u32 cur_adj = tk->tkr_mono.mult;
		s64 tick_error;
		bool negative;
		u32 adj;
		u32 adj_scale;

		/* Remove any current error adj from freq calculation */
		if (tk->ntp_err_mult)
		@@ -1690,13 +1693,33 @@ static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
		/* preserve the direction of correction */
		negative = (tick_error < 0);

		/* Sort out the magnitude of the correction */
		/* If any adjustment would pass the max, just return */
		if (negative && (cur_adj - 1) <= (base - max))
		return;
		if (!negative && (cur_adj + 1) >= (base + max))
		return;
		/*
		* Sort out the magnitude of the correction, but
		* avoid making so large a correction that we go
		* over the max adjustment.
		*/
		adj_scale = 0;
		tick_error = abs(tick_error);
		for (adj = 0; tick_error > interval; adj++)
		while (tick_error > interval) {
		u32 adj = 1 << (adj_scale + 1);

		/* Check if adjustment gets us within 1 unit from the max */
		if (negative && (cur_adj - adj) <= (base - max))
		break;
		if (!negative && (cur_adj + adj) >= (base + max))
		break;

		adj_scale++;
		tick_error >>= 1;
		}

		/* scale the corrections */
		timekeeping_apply_adjustment(tk, offset, negative, adj);
		timekeeping_apply_adjustment(tk, offset, negative, adj_scale);
		}

		/*