From 6c44cee772fbbf3d35698ed544079e02f4e7c97e Mon Sep 17 00:00:00 2001 From: Yang Zhang Date: Wed, 7 Mar 2012 07:34:55 +0000 Subject: [PATCH] RTC: fix 12-hour mode Hours in 12-hour mode are in the 1-12 range, not 0-11. Signed-off-by: Yang Zhang Committed-by: Keir Fraser --- xen/arch/x86/hvm/rtc.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c index ce3791f8be..b5fffc1634 100644 --- a/xen/arch/x86/hvm/rtc.c +++ b/xen/arch/x86/hvm/rtc.c @@ -168,6 +168,19 @@ static inline int from_bcd(RTCState *s, int a) return ((a >> 4) * 10) + (a & 0x0f); } +/* Hours in 12 hour mode are in 1-12 range, not 0-11. + * So we need convert it before using it*/ +static inline int convert_hour(RTCState *s, int hour) +{ + if (!(s->hw.cmos_data[RTC_REG_B] & RTC_24H)) + { + hour %= 12; + if (s->hw.cmos_data[RTC_HOURS] & 0x80) + hour += 12; + } + return hour; +} + static void rtc_set_time(RTCState *s) { struct tm *tm = &s->current_tm; @@ -182,9 +195,7 @@ static void rtc_set_time(RTCState *s) tm->tm_sec = from_bcd(s, s->hw.cmos_data[RTC_SECONDS]); tm->tm_min = from_bcd(s, s->hw.cmos_data[RTC_MINUTES]); tm->tm_hour = from_bcd(s, s->hw.cmos_data[RTC_HOURS] & 0x7f); - if ( !(s->hw.cmos_data[RTC_REG_B] & 0x02) && - (s->hw.cmos_data[RTC_HOURS] & 0x80) ) - tm->tm_hour += 12; + tm->tm_hour = convert_hour(s, tm->tm_hour); tm->tm_wday = from_bcd(s, s->hw.cmos_data[RTC_DAY_OF_WEEK]); tm->tm_mday = from_bcd(s, s->hw.cmos_data[RTC_DAY_OF_MONTH]); tm->tm_mon = from_bcd(s, s->hw.cmos_data[RTC_MONTH]) - 1; @@ -217,7 +228,8 @@ static void rtc_copy_date(RTCState *s) else { /* 12 hour format */ - s->hw.cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour % 12); + int h = (tm->tm_hour % 12) ? tm->tm_hour % 12 : 12; + s->hw.cmos_data[RTC_HOURS] = to_bcd(s, h); if ( tm->tm_hour >= 12 ) s->hw.cmos_data[RTC_HOURS] |= 0x80; } -- 2.39.5