From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + rtc-x1205-fix-rtc_time-to-y2k-register-value-conversion.patch added to -mm tree Date: Wed, 25 Nov 2009 14:11:09 -0800 Message-ID: <200911252211.nAPMB9mR031707@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:49381 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759525AbZKYWMB (ORCPT ); Wed, 25 Nov 2009 17:12:01 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: jw@emlix.com, a.zummo@towertech.it, p_gortmaker@yahoo.com The patch titled rtc-x1205: fix rtc_time to y2k register value conversion has been added to the -mm tree. Its filename is rtc-x1205-fix-rtc_time-to-y2k-register-value-conversion.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: rtc-x1205: fix rtc_time to y2k register value conversion From: Johannes Weiner The possible CCR_Y2K register values are 19 or 20 and struct rtc_time's tm_year is in years since 1900. The function translating rtc_time to register values assumes tm_year to be years since first christmas, though, and we end up storing 0 or 1 in the CCR_Y2K register, which the hardware does not refuse to do. A subsequent probing of the clock fails due to the invalid value range in the register, though. [ And if it didn't, reading the clock would yield a bogus year because the function translating registers to tm_year is assuming a register value of 19 or 20. ] This fixes the conversion from years since 1900 in tm_year to the corresponding CCR_Y2K value of 19 or 20. Signed-off-by: Johannes Weiner Cc: Alessandro Zummo Cc: Paul Gortmaker Signed-off-by: Andrew Morton --- drivers/rtc/rtc-x1205.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN drivers/rtc/rtc-x1205.c~rtc-x1205-fix-rtc_time-to-y2k-register-value-conversion drivers/rtc/rtc-x1205.c --- a/drivers/rtc/rtc-x1205.c~rtc-x1205-fix-rtc_time-to-y2k-register-value-conversion +++ a/drivers/rtc/rtc-x1205.c @@ -195,7 +195,7 @@ static int x1205_set_datetime(struct i2c /* year, since the rtc epoch*/ buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100); buf[CCR_WDAY] = tm->tm_wday & 0x07; - buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100); + buf[CCR_Y2K] = bin2bcd((tm->tm_year + 1900) / 100); } /* If writing alarm registers, set compare bits on registers 0-4 */ _ Patches currently in -mm which might be from jw@emlix.com are xtensa-use-generic-sys_pipe.patch rtc-x1205-fix-rtc_time-to-y2k-register-value-conversion.patch rtc-x1205-reset-clock-to-sane-state-after-power-failure.patch rtc-x1205-unconditionally-set-date-when-setting-clock.patch