When the RTC divider is changed from reset to an operating time base, the first update cycle should be 500ms later. But on some Zhaoxin SOCs, this first update cycle is one second later. So set RTC time on these Zhaoxin SOCs will causing 500ms delay. Skip setup RTC divider on these SOCs in mc146818_set_time to fix it. Signed-off-by: LeoLiu-oc <LeoLiu-oc@zhaoxin.com> ---  drivers/rtc/rtc-mc146818-lib.c | 16 ++++++++++++++++  1 file changed, 16 insertions(+) diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c index 2ecd8752b..96d9d0219 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -171,8 +171,17 @@ int mc146818_set_time(struct rtc_time *time)      save_control = CMOS_READ(RTC_CONTROL);      CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); +#ifdef CONFIG_X86 +    if (!((boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR || +           boot_cpu_data.x86_vendor == X86_VENDOR_ZHAOXIN) && +          (boot_cpu_data.x86 <= 7 && boot_cpu_data.x86_model <= 59))) { +        save_freq_select = CMOS_READ(RTC_FREQ_SELECT); +        CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); +    } +#else      save_freq_select = CMOS_READ(RTC_FREQ_SELECT);      CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); +#endif  #ifdef CONFIG_MACH_DECSTATION      CMOS_WRITE(real_yrs, RTC_DEC_YEAR); @@ -190,7 +199,14 @@ int mc146818_set_time(struct rtc_time *time)  #endif      CMOS_WRITE(save_control, RTC_CONTROL); +#ifdef CONFIG_X86 +    if (!((boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR || +           boot_cpu_data.x86_vendor == X86_VENDOR_ZHAOXIN) && +          (boot_cpu_data.x86 <= 7 && boot_cpu_data.x86_model <= 59))) +        CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); +#else      CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); +#endif      spin_unlock_irqrestore(&rtc_lock, flags); -- 2.20.1