kernel: Do not use sys_clock_ticks_per_sec in _ms_to_ticks() (3c7f9903) · Commits · Wenxi XU / zephyr

The value of sys_clock_ticks_per_sec is obtained using simple integer division with rounding toward zero. As result using this variable in _ms_to_ticks() introduces some error. This commit eliminates sys_clock_ticks_per_sec from equation used in _ms_to_ticks() removing introduced error. Also, this commit fixes #8895. Signed-off-by:

Piotr Zięcik <piotr.ziecik@nordicsemi.no>

include/kernel.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -1357,9 +1357,9 @@ static ALWAYS_INLINE s32_t _ms_to_ticks(s32_t ms)

		#ifdef _NEED_PRECISE_TICK_MS_CONVERSION
		/* use 64-bit math to keep precision */
		s64_t ms_ticks_per_sec = (s64_t)ms * sys_clock_ticks_per_sec;

		return (s32_t)ceiling_fraction(ms_ticks_per_sec, MSEC_PER_SEC);
		return (s32_t)ceiling_fraction(
		(s64_t)ms * sys_clock_hw_cycles_per_sec,
		(s64_t)MSEC_PER_SEC * sys_clock_hw_cycles_per_tick);
		#else
		/* simple division keeps precision */
		s32_t ms_per_tick = MSEC_PER_SEC / sys_clock_ticks_per_sec;

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