Q:am335x平臺內核系統時鐘比硬件時鐘快一倍
正常板子log信息
[ 0.000000] Total of 128 interrupts on 1 active controller
[ 0.000000] OMAP clockevent source: GPTIMER2 at 24000000 Hz
[ 0.000000] omap_dm_timer_switch_src: Switching to HW default clocksource(sys_clkin_ck) for timer1, this may impact timekeeping in low power state
[ 0.000000] OMAP clocksource: GPTIMER1 at 24000000 Hz
[ 0.000000] sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 178956ms
異常板子log信息
[ 0.000000]OMAP clocksource: GPTIMER1 at 32768 Hz AM335X
A:是由於外部硬件電路導致，參考可RTC_XTALIN、RTC_XTALOUT、VSS_RTC
RTC不准問題
OMAP clocksource: GPTIMER1 at 32768 Hz AM335X
https://e2echina.ti.com/question_answer/dsp_arm/sitara_arm/f/25/t/81166
TI官方論壇討論:OMAP clocksource: GPTIMER1 at 32768 Hz AM335X
原因：由於RTC_XTALIN、RTC_XTALOUT、VSS_RTC外圍電路配置