From: Ronan Dalton Date: Fri, 8 May 2026 03:24:49 +0000 (+1200) Subject: rtc: ds1307: handle oscillator stop flag for ds1337/ds1339/ds3231 X-Git-Tag: v7.2-rc1~7^2~26 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a091e1ba3b68cabc9caedafc6f81d9fe9b3b2200;p=thirdparty%2Fkernel%2Fstable.git rtc: ds1307: handle oscillator stop flag for ds1337/ds1339/ds3231 Prior to commit 48458654659c ("rtc: ds1307: remove clear of oscillator stop flag (OSF) in probe"), the oscillator stop flag (OSF) bit was checked during device probe for the ds1337, ds1339, ds1341, and ds3231 chips; if it was set, it would be cleared and a warning would be logged saying "SET TIME!". Since that commit, the OSF bit is no longer cleared, but the warning is still printed. Directly following that commit, there was no way to get rid of this warning because nothing cleared the OSF bit on these chips. The commit associated with the previous commit, 523923cfd5d6 ("rtc: ds1307: handle oscillator stop flag (OSF) for ds1341"), made proper use of the OSF when getting and setting the time in the RTC. However, the other RTC variants ds1337, ds1339 and ds3231 didn't have a corresponding change made. Given that the OSF bit is no longer cleared at probe time when it is set, the remaining three chips should have the same handling as the ds1341 chip has for the OSF bit. Fix the issue on the ds1337, ds1339 and ds3231 chips by applying the same logic as the ds1341 has to these chips. Note that any devices brought up between the first referenced commit and this one may begin mistrusting the time reported by the RTC until it is set again, if the bit was never explicitly cleared. Note that only the ds1339 was tested with this change, but the datasheets for the other chips contain essentially identical descriptions of the OSF bit so the same change should work. Signed-off-by: Ronan Dalton Cc: linux-rtc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Alexandre Belloni Cc: Tyler Hicks Cc: Sasha Levin Cc: Meagan Lloyd Cc: Rodolfo Giometti Cc: Chris Packham Fixes: 48458654659c ("rtc: ds1307: remove clear of oscillator stop flag (OSF) in probe") Reviewed-by: Meagan Lloyd Reviewed-by: Tyler Hicks Link: https://patch.msgid.link/20260508032518.3696705-2-ronan.dalton@alliedtelesis.co.nz Signed-off-by: Alexandre Belloni --- diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 7205c59ff7294..edf81b975decb 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -269,6 +269,16 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t) if (tmp & DS1338_BIT_OSF) return -EINVAL; break; + case ds_1337: + case ds_1339: + case ds_1341: + case ds_3231: + ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &tmp); + if (ret) + return ret; + if (tmp & DS1337_BIT_OSF) + return -EINVAL; + break; case ds_1340: if (tmp & DS1340_BIT_nEOSC) return -EINVAL; @@ -279,13 +289,6 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t) if (tmp & DS1340_BIT_OSF) return -EINVAL; break; - case ds_1341: - ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &tmp); - if (ret) - return ret; - if (tmp & DS1337_BIT_OSF) - return -EINVAL; - break; case ds_1388: ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &tmp); if (ret) @@ -380,14 +383,17 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t) regmap_update_bits(ds1307->regmap, DS1307_REG_CONTROL, DS1338_BIT_OSF, 0); break; - case ds_1340: - regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG, - DS1340_BIT_OSF, 0); - break; + case ds_1337: + case ds_1339: case ds_1341: + case ds_3231: regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS, DS1337_BIT_OSF, 0); break; + case ds_1340: + regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG, + DS1340_BIT_OSF, 0); + break; case ds_1388: regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG, DS1388_BIT_OSF, 0);