lkml.org 
[lkml]   [2010]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] x86, mrst: add explalation for using 1960 as the year offset for vrtc device
Date
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)
{


\
 
 \ /
  Last update: 2010-11-17 13:33    [W:0.046 / U:1.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site