From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752166AbbJXOpn (ORCPT ); Sat, 24 Oct 2015 10:45:43 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:46954 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750937AbbJXOpm (ORCPT ); Sat, 24 Oct 2015 10:45:42 -0400 Subject: Re: [PATCH] rtc: ds1307: Fix alarm programming for mcp794xx To: Tero Kristo , , References: <1445581797-19693-1-git-send-email-t-kristo@ti.com> CC: , , , From: Nishanth Menon Message-ID: <562B9955.40308@ti.com> Date: Sat, 24 Oct 2015 09:44:37 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1445581797-19693-1-git-send-email-t-kristo@ti.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/23/2015 01:29 AM, Tero Kristo wrote: > mcp794xx alarm registers must be written in BCD format. However, the > alarm programming logic neglected this by adding one to the value > after bin2bcd conversion has been already done, writing bad values > to month register in case the alarm being set is in October. In this > case, the alarm month value becomes 0x0a instead of the expected 0x10. > > Fix by moving the +1 addition within the bin2bcd call also. > > Fixes: 1d1945d261a2 ("drivers/rtc/rtc-ds1307.c: add alarm support for mcp7941x chips") > > Signed-off-by: Tero Kristo Nice catch. Acked-by: Nishanth Menon > --- > drivers/rtc/rtc-ds1307.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c > index a705e64..188006c 100644 > --- a/drivers/rtc/rtc-ds1307.c > +++ b/drivers/rtc/rtc-ds1307.c > @@ -718,9 +718,9 @@ static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t) > regs[3] = bin2bcd(t->time.tm_sec); > regs[4] = bin2bcd(t->time.tm_min); > regs[5] = bin2bcd(t->time.tm_hour); > - regs[6] = bin2bcd(t->time.tm_wday) + 1; > + regs[6] = bin2bcd(t->time.tm_wday + 1); > regs[7] = bin2bcd(t->time.tm_mday); > - regs[8] = bin2bcd(t->time.tm_mon) + 1; > + regs[8] = bin2bcd(t->time.tm_mon + 1); > > /* Clear the alarm 0 interrupt flag. */ > regs[6] &= ~MCP794XX_BIT_ALMX_IF; > -- Regards, Nishanth Menon