commit 00a39d8652 upstream.
cmos_interrupt() can be called in a non-interrupt context, such as in
an ACPI event handler (which runs in an interrupt thread). Therefore,
usage of spin_lock(&rtc_lock) is insecure. Use spin_lock_irqsave() /
spin_unlock_irqrestore() instead.
Before a misguided
commit 6950d046eb ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
the cmos_interrupt() function used spin_lock_irqsave(). That commit
changed it to spin_lock() and broke locking, which was partially fixed in
commit 13be2efc39 ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
That second commit did not take account of the ACPI fixed event handler
pathway, however. It introduced local_irq_disable() workarounds in
cmos_check_wkalrm(), which can cause problems on PREEMPT_RT kernels
and are now unnecessary.
Add an explicit comment so that this change will not be reverted by
mistake.
Cc: stable@vger.kernel.org
Fixes: 6950d046eb ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Closes: https://lore.kernel.org/all/aDtJ92foPUYmGheF@debian.local/
Link: https://lore.kernel.org/r/20250607210608.14835-1-mat.jonczyk@o2.pl
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8f2efdbc30 ]
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: dab5aec64b ("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>
commit fe9f5f96cf upstream.
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: 989515647e ("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: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7df4cfef8b 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>
[ Upstream commit 2b7cbd9849 ]
Power-on Reset has a documented issue in PCF85063, refer to its datasheet,
section "Software reset":
"There is a low probability that some devices will have corruption of the
registers after the automatic power-on reset if the device is powered up
with a residual VDD level. It is required that the VDD starts at zero volts
at power up or upon power cycling to ensure that there is no corruption of
the registers. If this is not possible, a reset must be initiated after
power-up (i.e. when power is stable) with the software reset command"
Trigger SW reset if there is an indication that POR has failed.
Link: https://www.nxp.com/docs/en/data-sheet/PCF85063A.pdf
Signed-off-by: Lukas Stockmann <lukas.stockmann@siemens.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20250120093451.30778-1-alexander.sverdlin@siemens.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0a6efab33e ]
On my device reading entirety of /sys/devices/pnp0/00:03/cmos_nvram0/nvmem
takes about 9 msec during which time interrupts are off on the CPU that
does the read and the thread that performs the read can not be migrated
or preempted by another higher priority thread (RT or not).
Allow readers and writers be preempted by taking and releasing rtc_lock
spinlock for each individual byte read or written rather than once per
read/write request.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Link: https://lore.kernel.org/r/Zxv8QWR21AV4ztC5@google.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e0779a0dcf ]
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: 67075b63cc ("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 e8ba8a2bc4 ]
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: 6610e0893b ("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 463927a890 ]
`rtc_add_offset()` is called by `__rtc_read_time()`
and `__rtc_read_alarm()` to add the RTC's offset to
the raw read-outs from the device drivers. However,
in the latter case, a fix-up algorithm is run if
the RTC device does not report a full `struct rtc_time`
alarm value. In that case, the offset was forgot to be
added.
Fixes: fd6792bb02 ("rtc: fix alarm read and set offset")
Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
Link: https://lore.kernel.org/r/20240619140451.2800578-1-csokas.bence@prolan.hu
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 95e7ebc682 upstream.
ds1685_rtc_poweroff is only used externally via symbol_get, which was
only ever intended for very internal symbols like this one. Use
EXPORT_SYMBOL_GPL for it so that symbol_get can enforce only being used
on EXPORT_SYMBOL_GPL symbols.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0e6255fa3f ]
The VRTC alarm register can be programmed with an amount of seconds
after which the SoC will be woken up by the VRTC timer again. We are
already converting the alarm time from meson_vrtc_set_alarm() to
"seconds since 1970". This means we also need to use "seconds since
1970" for the current time.
This fixes a problem where setting the alarm to one minute in the future
results in the firmware (which handles wakeup) to output (on the serial
console) that the system will be woken up in billions of seconds.
ktime_get_raw_ts64() returns the time since boot, not since 1970. Switch
to ktime_get_real_ts64() to fix the calculation of the alarm time and to
make the SoC wake up at the specified date/time. Also the firmware
(which manages suspend) now prints either 59 or 60 seconds until wakeup
(depending on how long it takes for the system to enter suspend).
Fixes: 6ef35398e8 ("rtc: Add Amlogic Virtual Wake RTC")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20230320212142.2355062-1-martin.blumenstingl@googlemail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 101ca8d059 upstream.
The current implementation of rtc-efi is expecting all the 4
time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
specific implementations can choose to enable selective time
services based on the RTC device capabilities.
This patch does the following changes to provide GET/SET RTC
services on platforms that do not support the WAKEUP feature.
1) Relax time services cap check when creating a platform device.
2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
3) Conditional alarm entries in '/proc/driver/rtc'.
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Link: https://lore.kernel.org/r/20230102230630.192911-1-sdonthineni@nvidia.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 08279468a2 ]
On 32-bit architectures with 64-bit resource_size_t, sp_rtc_probe()
causes a compiler warning:
drivers/rtc/rtc-sunplus.c: In function 'sp_rtc_probe':
drivers/rtc/rtc-sunplus.c:243:33: error: format '%x' expects argument of type 'unsigned int', but argument 4 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
243 | dev_dbg(&plat_dev->dev, "res = 0x%x, reg_base = 0x%lx\n",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The best way to print a resource is the special %pR format string,
and similarly to print a pointer we can use %p and avoid the cast.
Fixes: fad6cbe9b2 ("rtc: Add driver for RTC in Sunplus SP7021")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230117172450.2938962-1-arnd@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0462681e20 ]
On an iMX6ULL the following message appears when a wakealarm is set:
echo 0 > /sys/class/rtc/rtc1/wakealarm
rtc rtc1: Timeout trying to get valid LPSRT Counter read
This does not always happen but is reproducible quite often (7 out of 10
times). The problem appears because the iMX6ULL is not able to read the
registers within one 32kHz clock cycle which is the base clock of the
RTC. Therefore, this patch allows a difference of up to 320 cycles
(10ms). 10ms was chosen to be big enough even on systems with less cpu
power (e.g. iMX6ULL). According to the reference manual a difference is
fine:
- If the two consecutive reads are similar, the value is correct.
The values have to be similar, not equal.
Fixes: cd7f3a249d ("rtc: snvs: Add timeouts to avoid kernel lockups")
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco@dolcini.it>
Link: https://lore.kernel.org/r/20221106115915.7930-1-francesco@dolcini.it
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Mateusz Jończyk
Wolfram Sang
Alexandre Mergnat
Alexandre Belloni
Lukas Stockmann
Michal Simek
Oleksij Rempel
Dmitry Torokhov
Maxime Chevallier
Yongliang Gao
Nobuhiro Iwamatsu
Jinjie Ruan
Krzysztof Kozlowski
Joy Chakraborty
Csókás, Bence
Randy Dunlap
David Gow
Mario Limonciello
Javier Carrasco
Christoph Hellwig
Christophe JAILLET
Dhruva Gole
Martin Blumenstingl
Samuel Holland
Johan Hovold
Shanker Donthineni
Arnd Bergmann
Ian Abbott
Kees Cook
GUO Zihua
Gaosheng Cui
Alexander Stein
Stefan Eichenberger
Rafael J. Wysocki