From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760739Ab1CEBQf (ORCPT ); Fri, 4 Mar 2011 20:16:35 -0500 Received: from kroah.org ([198.145.64.141]:50198 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760322Ab1CEBAH (ORCPT ); Fri, 4 Mar 2011 20:00:07 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Mar 4 16:56:36 2011 Message-Id: <20110305005636.651906472@clark.kroah.org> User-Agent: quilt/0.48-11.2 Date: Fri, 04 Mar 2011 16:55:26 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Lei Xu , Alessandro Zummo , john stultz , Jack Lan Subject: [21/73] drivers/rtc/rtc-ds3232.c: fix time range difference between linux and RTC chip In-Reply-To: <20110305005720.GA16162@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.37-stable review patch. If anyone has any objections, please let us know. ------------------ From: Lei Xu 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 Cc: Alessandro Zummo Cc: john stultz Cc: Jack Lan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- 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 * * 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);