This is a note to let you know that I've just added the patch titled
drivers/rtc/rtc-ds3232.c: fix time range difference between linux and RTC
chip
to the 2.6.37-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-rtc-rtc-ds3232.c-fix-time-range-difference-between-linux-and-rtc-chip.patch
and it can be found in the queue-2.6.37 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From a2d6d2fa90c0e1d2cc1d59ccb5bbe93bb28b7413 Mon Sep 17 00:00:00 2001
From: Lei Xu <[email protected]>
Date: Fri, 25 Feb 2011 14:44:23 -0800
Subject: drivers/rtc/rtc-ds3232.c: fix time range difference between linux and
RTC chip
From: Lei Xu <[email protected]>
commit a2d6d2fa90c0e1d2cc1d59ccb5bbe93bb28b7413 upstream.
In linux rtc_time struct, tm_mon range is 0~11, tm_wday range is 0~6,
while in RTC HW REG, month range is 1~12, day of the week range is 1~7,
this patch adjusts difference of them.
The efect of this bug was that most of month will be operated on as the
next month by the hardware (When in Jan it maybe even worse). For
example, if in May, software wrote 4 to the hardware, which handled it as
April. Then the logic would be different between software and hardware,
which would cause weird things to happen.
Signed-off-by: Lei Xu <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: john stultz <[email protected]>
Cc: Jack Lan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/rtc/rtc-ds3232.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c
@@ -1,7 +1,7 @@
/*
* RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C
*
- * Copyright (C) 2009-2010 Freescale Semiconductor.
+ * Copyright (C) 2009-2011 Freescale Semiconductor.
* Author: Jack Lan <[email protected]>
*
* This program is free software; you can redistribute it and/or modify it
@@ -141,9 +141,11 @@ static int ds3232_read_time(struct devic
time->tm_hour = bcd2bin(hour);
}
- time->tm_wday = bcd2bin(week);
+ /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
+ time->tm_wday = bcd2bin(week) - 1;
time->tm_mday = bcd2bin(day);
- time->tm_mon = bcd2bin(month & 0x7F);
+ /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
+ time->tm_mon = bcd2bin(month & 0x7F) - 1;
if (century)
add_century = 100;
@@ -162,9 +164,11 @@ static int ds3232_set_time(struct device
buf[0] = bin2bcd(time->tm_sec);
buf[1] = bin2bcd(time->tm_min);
buf[2] = bin2bcd(time->tm_hour);
- buf[3] = bin2bcd(time->tm_wday); /* Day of the week */
+ /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
+ buf[3] = bin2bcd(time->tm_wday + 1);
buf[4] = bin2bcd(time->tm_mday); /* Date */
- buf[5] = bin2bcd(time->tm_mon);
+ /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
+ buf[5] = bin2bcd(time->tm_mon + 1);
if (time->tm_year >= 100) {
buf[5] |= 0x80;
buf[6] = bin2bcd(time->tm_year - 100);
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.37/drivers-rtc-rtc-ds3232.c-fix-time-range-difference-between-linux-and-rtc-chip.patch
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