Messages in this thread Patch in this message | | | From | Alan Cox <> | Subject | [PATCH] x86, mrst: add explalation for using 1960 as the year offset for vrtc device | Date | Wed, 17 Nov 2010 12:11:24 +0000 |
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From: Feng Tang <feng.tang@intel.com>
Explain the reason for the apparently odd choice of year offset so we don't get more questions about it.
Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> ---
drivers/rtc/rtc-mrst.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c index 67b6be2..bcd0cf6 100644 --- a/drivers/rtc/rtc-mrst.c +++ b/drivers/rtc/rtc-mrst.c @@ -66,7 +66,11 @@ static inline int is_intr(u8 rtc_intr) * rtc_time's year contains the increment over 1900, but vRTC's YEAR * register can't be programmed to value larger than 0x64, so vRTC * driver chose to use 1960 (1970 is UNIX time start point) as the base, - * and does the translation at read/write time + * and does the translation at read/write time. + * + * Why not just use 1970 as the offset? it's because using 1960 will + * make it consistent in leap year setting for both vrtc and low-level + * physical rtc devices. */ static int mrst_read_time(struct device *dev, struct rtc_time *time) {
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