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smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=jYyL7GkI; arc=none smtp.client-ip=217.70.183.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="jYyL7GkI" Received: by mail.gandi.net (Postfix) with ESMTPSA id A5D091BF206; Thu, 9 Jan 2025 15:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736437599; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=qcUXFptebfMrvGhDxe7112Zqb3/zYWm85RNBPbS8bvY=; b=jYyL7GkIne9oYb8FfybPUDkwzY0fOSPguU5OcA0GaTE7DAglUSKrm2ReCMMqXhdhwrsVAy KvktXwI+fOv6k6wxomXnn42zUPVNEgewwfXgQZlUbCAQ49Lbh88w3BQzvl8INX8Z51zEni v7+njmfFUctYEwS4KY3e3nFSeUAO6JcJu/4csGT0dmGZtwW82+iVg5XOrxnPrIruCp1xGS MZ58xCxKFtfkq3sWLgmrkIL1O0sBwGgdltStFiw7fIG1WSKGnT7Z3c3LS+bPnaIL3Hb0ym Zy1U+tdEEzP8SGCd1/d3/AxOChMUB2QjtBAJwmGIL/HSOZvaLa9HAP62R6ykEA== Date: Thu, 9 Jan 2025 16:46:38 +0100 From: Alexandre Belloni To: Alexandre Mergnat Cc: Eddie Huang , Sean Wang , Matthias Brugger , AngeloGioacchino Del Regno , Macpaul Lin , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] rtc: mt6359: fix year issue Message-ID: <202501091546387cff95fd@mail.local> References: <20250109-enable-rtc-v1-0-e8223bf55bb8@baylibre.com> <20250109-enable-rtc-v1-2-e8223bf55bb8@baylibre.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250109-enable-rtc-v1-2-e8223bf55bb8@baylibre.com> X-GND-Sasl: alexandre.belloni@bootlin.com On 09/01/2025 16:29:52+0100, Alexandre Mergnat wrote: > Removing the RTC_MIN_YEAR_OFFSET addition and subtraction has > introduced a regression. > > ~# hwclock -r --verbose > hwclock from util-linux 2.37.4 > System Time: 1262312013.143552 > Trying to open: /dev/rtc0 > Using the rtc interface to the clock. > Assuming hardware clock is kept in UTC time. > Waiting for clock tick... > hwclock: select() to /dev/rtc0 to wait for clock tick timed out > ...synchronization failed > > Bring back the RTC_MIN_YEAR_OFFSET to fix the RTC. > NAK, you'd have to investigate a bit more, I want to get rid of the RTC_MIN_YEAR_OFFSET insanity. > Fixes: 34bbdc12d04e ("rtc: mt6359: Add RTC hardware range and add support for start-year") > Signed-off-by: Alexandre Mergnat > --- > drivers/rtc/rtc-mt6397.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c > index 55e75712edd4..9930b6bdb6ca 100644 > --- a/drivers/rtc/rtc-mt6397.c > +++ b/drivers/rtc/rtc-mt6397.c > @@ -96,6 +96,12 @@ static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm) > goto exit; > } while (sec < tm->tm_sec); > > + /* HW register use 7 bits to store year data, minus > + * RTC_MIN_YEAR_OFFSET before write year data to register, and plus > + * RTC_MIN_YEAR_OFFSET back after read year from register > + */ > + tm->tm_year += RTC_MIN_YEAR_OFFSET; > + > /* HW register start mon/wday from one, but tm_mon/tm_wday start from zero. */ > tm->tm_mon--; > tm->tm_wday--; > @@ -110,6 +116,7 @@ static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm) > int ret; > u16 data[RTC_OFFSET_COUNT]; > > + tm->tm_year -= RTC_MIN_YEAR_OFFSET; > tm->tm_mon++; > tm->tm_wday++; > > @@ -167,6 +174,7 @@ static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) > tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK; > tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK; > > + tm->tm_year += RTC_MIN_YEAR_OFFSET; > tm->tm_mon--; > > return 0; > @@ -182,6 +190,7 @@ static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) > int ret; > u16 data[RTC_OFFSET_COUNT]; > > + tm->tm_year -= RTC_MIN_YEAR_OFFSET; > tm->tm_mon++; > > mutex_lock(&rtc->lock); > > -- > 2.25.1 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com