linux-stable.git/drivers/rtc, branch v5.4.296 Linux kernel stable tree rtc: test: Fix invalid format specifier. 2025-06-27T10:02:58+00:00 David Gow davidgow@google.com 2024-02-21T09:27:18+00:00 b9dc8b84b9e5375cd239b2c56dc2b8c765bbd431 commit 8a904a3caa88118744062e872ae90f37748a8fd8 upstream. 'days' is a s64 (from div_s64), and so should use a %lld specifier. This was found by extending KUnit's assertion macros to use gcc's __printf attribute. Fixes: 1d1bb12a8b18 ("rtc: Improve performance of rtc_time64_to_tm(). Add tests.") Signed-off-by: David Gow <davidgow@google.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Justin Stitt <justinstitt@google.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8a904a3caa88118744062e872ae90f37748a8fd8 upstream.

'days' is a s64 (from div_s64), and so should use a %lld specifier.

This was found by extending KUnit's assertion macros to use gcc's
__printf attribute.

Fixes: 1d1bb12a8b18 ("rtc: Improve performance of rtc_time64_to_tm(). Add tests.")
Signed-off-by: David Gow <davidgow@google.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: Make rtc_time64_to_tm() support dates before 1970 2025-06-27T10:02:58+00:00 Alexandre Mergnat amergnat@baylibre.com 2025-04-28T10:06:47+00:00 afef20f48875e578e3a90509074c7c02967333eb commit 7df4cfef8b351fec3156160bedfc7d6d29de4cce upstream. Conversion of dates before 1970 is still relevant today because these dates are reused on some hardwares to store dates bigger than the maximal date that is representable in the device's native format. This prominently and very soon affects the hardware covered by the rtc-mt6397 driver that can only natively store dates in the interval 1900-01-01 up to 2027-12-31. So to store the date 2028-01-01 00:00:00 to such a device, rtc_time64_to_tm() must do the right thing for time=-2208988800. Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-1-2b2f7e3f9349@baylibre.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7df4cfef8b351fec3156160bedfc7d6d29de4cce upstream.

Conversion of dates before 1970 is still relevant today because these
dates are reused on some hardwares to store dates bigger than the
maximal date that is representable in the device's native format.
This prominently and very soon affects the hardware covered by the
rtc-mt6397 driver that can only natively store dates in the interval
1900-01-01 up to 2027-12-31. So to store the date 2028-01-01 00:00:00
to such a device, rtc_time64_to_tm() must do the right thing for
time=-2208988800.

Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-1-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: Improve performance of rtc_time64_to_tm(). Add tests. 2025-06-27T10:02:58+00:00 Cassio Neri cassio.neri@gmail.com 2021-06-24T20:13:43+00:00 31d87dda792b819daf028488dcb4dd3206c2a9cd commit 1d1bb12a8b1805ddeef9793ebeb920179fb0fa38 upstream. The current implementation of rtc_time64_to_tm() contains unnecessary loops, branches and look-up tables. The new one uses an arithmetic-based algorithm appeared in [1] and is approximately 4.3 times faster (YMMV). The drawback is that the new code isn't intuitive and contains many 'magic numbers' (not unusual for this type of algorithm). However, [1] justifies all those numbers and, given this function's history, the code is unlikely to need much maintenance, if any at all. Add a KUnit test case that checks every day in a 160,000 years interval starting on 1970-01-01 against the expected result. Add a new config RTC_LIB_KUNIT_TEST symbol to give the option to run this test suite. [1] Neri, Schneider, "Euclidean Affine Functions and Applications to Calendar Algorithms". https://arxiv.org/abs/2102.06959 Signed-off-by: Cassio Neri <cassio.neri@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210624201343.85441-1-cassio.neri@gmail.com Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1d1bb12a8b1805ddeef9793ebeb920179fb0fa38 upstream.

The current implementation of rtc_time64_to_tm() contains unnecessary
loops, branches and look-up tables. The new one uses an arithmetic-based
algorithm appeared in [1] and is approximately 4.3 times faster (YMMV).

The drawback is that the new code isn't intuitive and contains many 'magic
numbers' (not unusual for this type of algorithm). However, [1] justifies
all those numbers and, given this function's history, the code is unlikely
to need much maintenance, if any at all.

Add a KUnit test case that checks every day in a 160,000 years interval
starting on 1970-01-01 against the expected result. Add a new config
RTC_LIB_KUNIT_TEST symbol to give the option to run this test suite.

[1] Neri, Schneider, "Euclidean Affine Functions and Applications to
Calendar Algorithms". https://arxiv.org/abs/2102.06959

Signed-off-by: Cassio Neri <cassio.neri@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210624201343.85441-1-cassio.neri@gmail.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: Fix offset calculation for .start_secs < 0 2025-06-27T10:02:48+00:00 Alexandre Mergnat amergnat@baylibre.com 2025-04-28T10:06:48+00:00 55d4b2734f48cdb20cdd272b580d1f3a4ed7d6e2 [ Upstream commit fe9f5f96cfe8b82d0f24cbfa93718925560f4f8d ] The comparison rtc->start_secs > rtc->range_max has a signed left-hand side and an unsigned right-hand side. So the comparison might become true for negative start_secs which is interpreted as a (possibly very large) positive value. As a negative value can never be bigger than an unsigned value the correct representation of the (mathematical) comparison rtc->start_secs > rtc->range_max in C is: rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max Use that to fix the offset calculation currently used in the rtc-mt6397 driver. Fixes: 989515647e783 ("rtc: Add one offset seconds to expand RTC range") Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-2-2b2f7e3f9349@baylibre.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fe9f5f96cfe8b82d0f24cbfa93718925560f4f8d ]

The comparison

        rtc->start_secs > rtc->range_max

has a signed left-hand side and an unsigned right-hand side.
So the comparison might become true for negative start_secs which is
interpreted as a (possibly very large) positive value.

As a negative value can never be bigger than an unsigned value
the correct representation of the (mathematical) comparison

        rtc->start_secs > rtc->range_max

in C is:

        rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max

Use that to fix the offset calculation currently used in the
rtc-mt6397 driver.

Fixes: 989515647e783 ("rtc: Add one offset seconds to expand RTC range")
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-2-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtc: sh: assign correct interrupts with DT 2025-06-27T10:02:48+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2025-02-27T13:42:56+00:00 5023b76466ce3bd6d5074fd4dffd33b10d9fe844 [ Upstream commit 8f2efdbc303fe7baa83843d3290dd6ea5ba3276c ] The DT bindings for this driver define the interrupts in the order as they are numbered in the interrupt controller. The old platform_data, however, listed them in a different order. So, for DT based platforms, they are mixed up. Assign them specifically for DT, so we can keep the bindings stable. After the fix, 'rtctest' passes again on the Renesas Genmai board (RZ-A1 / R7S72100). Fixes: dab5aec64bf5 ("rtc: sh: add support for rza series") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20250227134256.9167-11-wsa+renesas@sang-engineering.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8f2efdbc303fe7baa83843d3290dd6ea5ba3276c ]

The DT bindings for this driver define the interrupts in the order as
they are numbered in the interrupt controller. The old platform_data,
however, listed them in a different order. So, for DT based platforms,
they are mixed up. Assign them specifically for DT, so we can keep the
bindings stable. After the fix, 'rtctest' passes again on the Renesas
Genmai board (RZ-A1 / R7S72100).

Fixes: dab5aec64bf5 ("rtc: sh: add support for rza series")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20250227134256.9167-11-wsa+renesas@sang-engineering.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtc: ds1307: stop disabling alarms on probe 2025-06-04T12:32:31+00:00 Alexandre Belloni alexandre.belloni@bootlin.com 2025-03-03T22:37:44+00:00 cadb64fea4a74a7d298ca78e25ae0529552e4c8f [ Upstream commit dcec12617ee61beed928e889607bf37e145bf86b ] It is a bad practice to disable alarms on probe or remove as this will prevent alarms across reboots. Link: https://lore.kernel.org/r/20250303223744.1135672-1-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dcec12617ee61beed928e889607bf37e145bf86b ]

It is a bad practice to disable alarms on probe or remove as this will
prevent alarms across reboots.

Link: https://lore.kernel.org/r/20250303223744.1135672-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read 2025-03-13T11:42:59+00:00 Oleksij Rempel o.rempel@pengutronix.de 2024-12-18T19:34:58+00:00 21cd59fcb9952eb7505da2bdfc1eb9c619df3ff4 [ Upstream commit 3ab8c5ed4f84fa20cd16794fe8dc31f633fbc70c ] The nvmem interface supports variable buffer sizes, while the regmap interface operates with fixed-size storage. If an nvmem client uses a buffer size less than 4 bytes, regmap_read will write out of bounds as it expects the buffer to point at an unsigned int. Fix this by using an intermediary unsigned int to hold the value. Fixes: fadfd092ee91 ("rtc: pcf85063: add nvram support") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20241218-rtc-pcf85063-stack-corruption-v1-1-12fd0ee0f046@pengutronix.de Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3ab8c5ed4f84fa20cd16794fe8dc31f633fbc70c ]

The nvmem interface supports variable buffer sizes, while the regmap
interface operates with fixed-size storage. If an nvmem client uses a
buffer size less than 4 bytes, regmap_read will write out of bounds
as it expects the buffer to point at an unsigned int.

Fix this by using an intermediary unsigned int to hold the value.

Fixes: fadfd092ee91 ("rtc: pcf85063: add nvram support")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20241218-rtc-pcf85063-stack-corruption-v1-1-12fd0ee0f046@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtc: ab-eoz9: don't fail temperature reads on undervoltage notification 2024-12-14T18:44:41+00:00 Maxime Chevallier maxime.chevallier@bootlin.com 2024-11-22T10:10:30+00:00 4c54ffc23bcec2e0bbc1cfd572d98ad2eefdf524 [ Upstream commit e0779a0dcf41a6452ac0a169cd96863feb5787c7 ] The undervoltage flags reported by the RTC are useful to know if the time and date are reliable after a reboot. Although the threshold VLOW1 indicates that the thermometer has been shutdown and time compensation is off, it doesn't mean that the temperature readout is currently impossible. As the system is running, the RTC voltage is now fully established and we can read the temperature. Fixes: 67075b63cce2 ("rtc: add AB-RTCMC-32.768kHz-EOZ9 RTC support") Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://lore.kernel.org/r/20241122101031.68916-3-maxime.chevallier@bootlin.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e0779a0dcf41a6452ac0a169cd96863feb5787c7 ]

The undervoltage flags reported by the RTC are useful to know if the
time and date are reliable after a reboot. Although the threshold VLOW1
indicates that the thermometer has been shutdown and time compensation
is off, it doesn't mean that the temperature readout is currently
impossible.

As the system is running, the RTC voltage is now fully established and
we can read the temperature.

Fixes: 67075b63cce2 ("rtc: add AB-RTCMC-32.768kHz-EOZ9 RTC support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://lore.kernel.org/r/20241122101031.68916-3-maxime.chevallier@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtc: check if __rtc_read_time was successful in rtc_timer_do_work() 2024-12-14T18:44:40+00:00 Yongliang Gao leonylgao@tencent.com 2024-10-11T04:31:53+00:00 44b3257ff705d63d5f00ef8ed314a0eeb7ec37f2 [ Upstream commit e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d ] If the __rtc_read_time call fails,, the struct rtc_time tm; may contain uninitialized data, or an illegal date/time read from the RTC hardware. When calling rtc_tm_to_ktime later, the result may be a very large value (possibly KTIME_MAX). If there are periodic timers in rtc->timerqueue, they will continually expire, may causing kernel softlockup. Fixes: 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events") Signed-off-by: Yongliang Gao <leonylgao@tencent.com> Acked-by: Jingqun Li <jingqunli@tencent.com> Link: https://lore.kernel.org/r/20241011043153.3788112-1-leonylgao@gmail.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d ]

If the __rtc_read_time call fails,, the struct rtc_time tm; may contain
uninitialized data, or an illegal date/time read from the RTC hardware.

When calling rtc_tm_to_ktime later, the result may be a very large value
(possibly KTIME_MAX). If there are periodic timers in rtc->timerqueue,
they will continually expire, may causing kernel softlockup.

Fixes: 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events")
Signed-off-by: Yongliang Gao <leonylgao@tencent.com>
Acked-by: Jingqun Li <jingqunli@tencent.com>
Link: https://lore.kernel.org/r/20241011043153.3788112-1-leonylgao@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtc: abx80x: Fix WDT bit position of the status register 2024-12-14T18:44:40+00:00 Nobuhiro Iwamatsu iwamatsu@nigauri.org 2024-10-08T04:17:37+00:00 1a7d4c093bcf42ce65256bc54df44c63380d660e [ Upstream commit 10e078b273ee7a2b8b4f05a64ac458f5e652d18d ] The WDT bit in the status register is 5, not 6. This fixes from 6 to 5. Link: https://abracon.com/Support/AppsManuals/Precisiontiming/AB08XX-Application-Manual.pdf Link: https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-1805-C3_App-Manual.pdf Fixes: 749e36d0a0d7 ("rtc: abx80x: add basic watchdog support") Cc: Jeremy Gebben <jgebben@sweptlaser.com> Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org> Link: https://lore.kernel.org/r/20241008041737.1640633-1-iwamatsu@nigauri.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 10e078b273ee7a2b8b4f05a64ac458f5e652d18d ]

The WDT bit in the status register is 5, not 6. This fixes from 6 to 5.

Link: https://abracon.com/Support/AppsManuals/Precisiontiming/AB08XX-Application-Manual.pdf
Link: https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-1805-C3_App-Manual.pdf
Fixes: 749e36d0a0d7 ("rtc: abx80x: add basic watchdog support")
Cc: Jeremy Gebben <jgebben@sweptlaser.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Link: https://lore.kernel.org/r/20241008041737.1640633-1-iwamatsu@nigauri.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>