Commit Graph

3769 Commits

Author SHA1 Message Date
Martin Blumenstingl
9e5a7c1106 rtc: meson-vrtc: Use ktime_get_real_ts64() to get the current time
[ Upstream commit 0e6255fa3f649170da6bd1a544680589cfae1131 ]

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>
2023-05-17 11:48:01 +02:00
Krzysztof Kozlowski
889a2070dc rtc: omap: include header for omap_rtc_power_off_program prototype
[ Upstream commit f69c2b5420497b7a54181ce170d682cbeb1f119f ]

Non-static functions should have a prototype:

  drivers/rtc/rtc-omap.c:410:5: error: no previous prototype for ‘omap_rtc_power_off_program’ [-Werror=missing-prototypes]

Fixes: 6256f7f7f2 ("rtc: OMAP: Add support for rtc-only mode")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230311094021.79730-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17 11:48:01 +02:00
Samuel Holland
555f315832 rtc: sun6i: Always export the internal oscillator
[ Upstream commit 344f4030f6c50a9db2d03021884c4bf36191b53a ]

On all variants of the hardware, the internal oscillator is one possible
parent for the AR100 clock. It needs to be exported so we can model that
relationship correctly in the devicetree.

Fixes: c56afc1844 ("rtc: sun6i: Expose internal oscillator through device tree")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20221229215319.14145-1-samuel@sholland.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:40:14 +01:00
Johan Hovold
66b40f8756 rtc: pm8xxx: fix set-alarm race
commit c88db0eff9722fc2b6c4d172a50471d20e08ecc6 upstream.

Make sure to disable the alarm before updating the four alarm time
registers to avoid spurious alarms during the update.

Note that the disable needs to be done outside of the ctrl_reg_lock
section to prevent a racing alarm interrupt from disabling the newly set
alarm when the lock is released.

Fixes: 9a9a54ad7a ("drivers/rtc: add support for Qualcomm PMIC8xxx RTC")
Cc: stable@vger.kernel.org      # 3.1
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: David Collins <quic_collinsd@quicinc.com>
Link: https://lore.kernel.org/r/20230202155448.6715-2-johan+linaro@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 16:39:54 +01:00
Ian Abbott
e94443252b rtc: ds1347: fix value written to century register
commit 4dfe05bdc1ade79b943d4979a2e2a8b5ef68fbb5 upstream.

In `ds1347_set_time()`, the wrong value is being written to the
`DS1347_CENTURY_REG` register.  It needs to be converted to BCD.  Fix
it.

Fixes: 147dae76db ("rtc: ds1347: handle century register")
Cc: <stable@vger.kernel.org> # v5.5+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20221027163249.447416-1-abbotti@mev.co.uk
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:34 +01:00
GUO Zihua
57ce1a36c0 rtc: mxc_v2: Add missing clk_disable_unprepare()
[ Upstream commit 55d5a86618d3b1a768bce01882b74cbbd2651975 ]

The call to clk_disable_unprepare() is left out in the error handling of
devm_rtc_allocate_device. Add it back.

Fixes: 5490a1e018 ("rtc: mxc_v2: fix possible race condition")
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Link: https://lore.kernel.org/r/20221122085046.21689-1-guozihua@huawei.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:11 +01:00
Alexandre Belloni
09c007e239 rtc: pcf85063: fix pcf85063_clkout_control
[ Upstream commit c2d12e85336f6d4172fb2bab5935027c446d7343 ]

pcf85063_clkout_control reads the wrong register but then update the
correct one.

Reported-by: Janne Terho <janne.terho@ouman.fi>
Fixes: 8c229ab604 ("rtc: pcf85063: Add pcf85063 clkout control to common clock framework")
Link: https://lore.kernel.org/r/20221211223553.59955-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:09 +01:00
Gaosheng Cui
e9453c13ae rtc: pic32: Move devm_rtc_allocate_device earlier in pic32_rtc_probe()
[ Upstream commit 90cd5c88830140c9fade92a8027e0fb2c6e4cc49 ]

The pic32_rtc_enable(pdata, 0) and clk_disable_unprepare(pdata->clk)
should be called in the error handling of devm_rtc_allocate_device(),
so we should move devm_rtc_allocate_device earlier in pic32_rtc_probe()
to fix it.

Fixes: 6515e23b9f ("rtc: pic32: convert to devm_rtc_allocate_device")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221123015953.1998521-1-cuigaosheng1@huawei.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:09 +01:00
Gaosheng Cui
34836c5923 rtc: st-lpc: Add missing clk_disable_unprepare in st_rtc_probe()
[ Upstream commit 5fb733d7bd6949e90028efdce8bd528c6ab7cf1e ]

The clk_disable_unprepare() should be called in the error handling
of clk_get_rate(), fix it.

Fixes: b5b2bdfc28 ("rtc: st: Add new driver for ST's LPC RTC")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221123014805.1993052-1-cuigaosheng1@huawei.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:09 +01:00
Alexander Stein
3929576f10 rtc: pcf85063: Fix reading alarm
[ Upstream commit a6ceee26fd5ed9b5bd37322b1ca88e4548cee4a3 ]

If the alarms are disabled the topmost bit (AEN_*) is set in the alarm
registers. This is also interpreted in BCD number leading to this warning:
rtc rtc0: invalid alarm value: 2022-09-21T80:80:80

Fix this by masking alarm enabling and reserved bits.

Fixes: 05cb3a56ee ("rtc: pcf85063: add alarm support")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220921074141.3903104-1-alexander.stein@ew.tq-group.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:05 +01:00
Stefan Eichenberger
aaed333e22 rtc: snvs: Allow a time difference on clock register read
[ Upstream commit 0462681e207ccc44778a77b3297af728b1cf5b9f ]

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>
2023-01-14 10:16:05 +01:00
Rafael J. Wysocki
f0c36ea424 rtc: cmos: Disable ACPI RTC event on removal
[ Upstream commit 83ebb7b3036d151ee39a4a752018665648fc3bd4 ]

Make cmos_do_remove() drop the ACPI RTC fixed event handler so as to
prevent it from operating on stale data in case the event triggers
after driver removal.

Fixes: 311ee9c151 ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/2224609.iZASKD2KPV@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:05 +01:00
Rafael J. Wysocki
ca8cb20c22 rtc: cmos: Rename ACPI-related functions
[ Upstream commit d13e9ad9f5146f066a5c5a1cc993d09e4fb21ead ]

The names of rtc_wake_setup() and cmos_wake_setup() don't indicate
that these functions are ACPI-related, which is the case, and the
former doesn't really reflect the role of the function.

Rename them to acpi_rtc_event_setup() and acpi_cmos_wake_setup(),
respectively, to address this shortcoming.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/3225614.44csPzL39Z@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:05 +01:00
Rafael J. Wysocki
9f9923baa2 rtc: cmos: Eliminate forward declarations of some functions
[ Upstream commit dca4d3b71c8a09a16951add656711fbd6f5bfbb0 ]

Reorder the ACPI-related code before cmos_do_probe() so as to eliminate
excessive forward declarations of some functions.

While at it, for consistency, add the inline modifier to the
definitions of empty stub static funtions and remove it from the
corresponding definitions of functions with non-empty bodies.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/13157911.uLZWGnKmhe@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:05 +01:00
Rafael J. Wysocki
462db582e8 rtc: cmos: Call rtc_wake_setup() from cmos_do_probe()
[ Upstream commit 375bbba09692fe4c5218eddee8e312dd733fa846 ]

To reduce code duplication, move the invocation of rtc_wake_setup()
into cmos_do_probe() and simplify the callers of the latter.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/2143522.irdbgypaU6@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:05 +01:00
Rafael J. Wysocki
14ad1353c5 rtc: cmos: Call cmos_wake_setup() from cmos_do_probe()
[ Upstream commit 508ccdfb86b21da37ad091003a4d4567709d5dfb ]

Notice that cmos_wake_setup() is the only user of acpi_rtc_info and it
can operate on the cmos_rtc variable directly, so it need not set the
platform_data pointer before cmos_do_probe() is called.  Instead, it
can be called by cmos_do_probe() in the case when the platform_data
pointer is not set to implement the default behavior (which is to use
the FADT information as long as ACPI support is enabled).

Modify the code accordingly.

While at it, drop a comment that doesn't really match the code it is
supposed to be describing.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/4803444.31r3eYUQgx@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:04 +01:00
Alexandre Belloni
45b96601a6 rtc: cmos: fix build on non-ACPI platforms
[ Upstream commit db4e955ae333567dea02822624106c0b96a2f84f ]

Now that rtc_wake_setup is called outside of cmos_wake_setup, it also need
to be defined on non-ACPI platforms.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20221018203512.2532407-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:04 +01:00
Rafael J. Wysocki
f2ece2c722 rtc: cmos: Fix wake alarm breakage
[ Upstream commit 0782b66ed2fbb035dda76111df0954515e417b24 ]

Commit 4919d3eb2ec0 ("rtc: cmos: Fix event handler registration
ordering issue") overlooked the fact that cmos_do_probe() depended
on the preparations carried out by cmos_wake_setup() and the wake
alarm stopped working after the ordering of them had been changed.

Address this by partially reverting commit 4919d3eb2ec0 so that
cmos_wake_setup() is called before cmos_do_probe() again and moving
the rtc_wake_setup() invocation from cmos_wake_setup() directly to the
callers of cmos_do_probe() where it will happen after a successful
completion of the latter.

Fixes: 4919d3eb2ec0 ("rtc: cmos: Fix event handler registration ordering issue")
Reported-by: Zhang Rui <rui.zhang@intel.com>
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/5887691.lOV4Wx5bFT@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:04 +01:00
Rafael J. Wysocki
0bcfccb486 rtc: cmos: Fix event handler registration ordering issue
[ Upstream commit 4919d3eb2ec0ee364f7e3cf2d99646c1b224fae8 ]

Because acpi_install_fixed_event_handler() enables the event
automatically on success, it is incorrect to call it before the
handler routine passed to it is ready to handle events.

Unfortunately, the rtc-cmos driver does exactly the incorrect thing
by calling cmos_wake_setup(), which passes rtc_handler() to
acpi_install_fixed_event_handler(), before cmos_do_probe(), because
rtc_handler() uses dev_get_drvdata() to get to the cmos object
pointer and the driver data pointer is only populated in
cmos_do_probe().

This leads to a NULL pointer dereference in rtc_handler() on boot
if the RTC fixed event happens to be active at the init time.

To address this issue, change the initialization ordering of the
driver so that cmos_wake_setup() is always called after a successful
cmos_do_probe() call.

While at it, change cmos_pnp_probe() to call cmos_do_probe() after
the initial if () statement used for computing the IRQ argument to
be passed to cmos_do_probe() which is cleaner than calling it in
each branch of that if () (local variable "irq" can be of type int,
because it is passed to that function as an argument of type int).

Note that commit 6492fed7d8c9 ("rtc: rtc-cmos: Do not check
ACPI_FADT_LOW_POWER_S0") caused this issue to affect a larger number
of systems, because previously it only affected systems with
ACPI_FADT_LOW_POWER_S0 set, but it is present regardless of that
commit.

Fixes: 6492fed7d8c9 ("rtc: rtc-cmos: Do not check ACPI_FADT_LOW_POWER_S0")
Fixes: a474aaedac ("rtc-cmos: move wake setup from ACPI glue into RTC driver")
Link: https://lore.kernel.org/linux-acpi/20221010141630.zfzi7mk7zvnmclzy@techsingularity.net/
Reported-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/5629262.DvuYhMxLoT@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:04 +01:00
Rafael J. Wysocki
5814d77e2f rtc: rtc-cmos: Do not check ACPI_FADT_LOW_POWER_S0
[ Upstream commit 6492fed7d8c95f53b0b804ef541324d924d95d41 ]

The ACPI_FADT_LOW_POWER_S0 flag merely means that it is better to
use low-power S0 idle on the given platform than S3 (provided that
the latter is supported) and it doesn't preclude using either of
them (which of them will be used depends on the choices made by user
space).

For this reason, there is no benefit from checking that flag in
use_acpi_alarm_quirks().

First off, it cannot be a bug to do S3 with use_acpi_alarm set,
because S3 can be used on systems with ACPI_FADT_LOW_POWER_S0 and it
must work if really supported, so the ACPI_FADT_LOW_POWER_S0 check is
not needed to protect the S3-capable systems from failing.

Second, suspend-to-idle can be carried out on a system with
ACPI_FADT_LOW_POWER_S0 unset and it is expected to work, so if setting
use_acpi_alarm is needed to handle that case correctly, it should be
set regardless of the ACPI_FADT_LOW_POWER_S0 value.

Accordingly, drop the ACPI_FADT_LOW_POWER_S0 check from
use_acpi_alarm_quirks().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/12054246.O9o76ZdvQC@kreacher
Stable-dep-of: 83ebb7b3036d ("rtc: cmos: Disable ACPI RTC event on removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:04 +01:00
Dan Carpenter
cb283cca1d rtc: mc146818-lib: fix signedness bug in mc146818_get_time()
[ Upstream commit 7372971c1be5b7d4fdd8ad237798bdc1d1d54162 ]

The mc146818_get_time() function returns zero on success or negative
a error code on failure.  It needs to be type int.

Fixes: d35786b3a28d ("rtc: mc146818-lib: change return values of mc146818_get_time()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220111071922.GE11243@kili
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:59 +01:00
Mateusz Jończyk
5c432383b6 rtc: mc146818-lib: fix locking in mc146818_set_time
[ Upstream commit 811f5559270f25c34c338d6eaa2ece2544c3d3bd ]

In mc146818_set_time(), CMOS_READ(RTC_CONTROL) was performed without the
rtc_lock taken, which is required for CMOS accesses. Fix this.

Nothing in kernel modifies RTC_DM_BINARY, so a separate critical section
is allowed here.

Fixes: dcf257e92622 ("rtc: mc146818: Reduce spinlock section in mc146818_set_time()")
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220220090403.153928-1-mat.jonczyk@o2.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:59 +01:00
Chris Wilson
5e26531d81 rtc: cmos: Disable irq around direct invocation of cmos_interrupt()
[ Upstream commit 13be2efc390acd2a46a69a359f6efc00ca434599 ]

As previously noted in commit 66e4f4a9cc ("rtc: cmos: Use
spin_lock_irqsave() in cmos_interrupt()"):

<4>[  254.192378] WARNING: inconsistent lock state
<4>[  254.192384] 5.12.0-rc1-CI-CI_DRM_9834+ #1 Not tainted
<4>[  254.192396] --------------------------------
<4>[  254.192400] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
<4>[  254.192409] rtcwake/5309 [HC0[0]:SC0[0]:HE1:SE1] takes:
<4>[  254.192429] ffffffff8263c5f8 (rtc_lock){?...}-{2:2}, at: cmos_interrupt+0x18/0x100
<4>[  254.192481] {IN-HARDIRQ-W} state was registered at:
<4>[  254.192488]   lock_acquire+0xd1/0x3d0
<4>[  254.192504]   _raw_spin_lock+0x2a/0x40
<4>[  254.192519]   cmos_interrupt+0x18/0x100
<4>[  254.192536]   rtc_handler+0x1f/0xc0
<4>[  254.192553]   acpi_ev_fixed_event_detect+0x109/0x13c
<4>[  254.192574]   acpi_ev_sci_xrupt_handler+0xb/0x28
<4>[  254.192596]   acpi_irq+0x13/0x30
<4>[  254.192620]   __handle_irq_event_percpu+0x43/0x2c0
<4>[  254.192641]   handle_irq_event_percpu+0x2b/0x70
<4>[  254.192661]   handle_irq_event+0x2f/0x50
<4>[  254.192680]   handle_fasteoi_irq+0x9e/0x150
<4>[  254.192693]   __common_interrupt+0x76/0x140
<4>[  254.192715]   common_interrupt+0x96/0xc0
<4>[  254.192732]   asm_common_interrupt+0x1e/0x40
<4>[  254.192750]   _raw_spin_unlock_irqrestore+0x38/0x60
<4>[  254.192767]   resume_irqs+0xba/0xf0
<4>[  254.192786]   dpm_resume_noirq+0x245/0x3d0
<4>[  254.192811]   suspend_devices_and_enter+0x230/0xaa0
<4>[  254.192835]   pm_suspend.cold.8+0x301/0x34a
<4>[  254.192859]   state_store+0x7b/0xe0
<4>[  254.192879]   kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.192899]   new_sync_write+0x11d/0x1b0
<4>[  254.192916]   vfs_write+0x265/0x390
<4>[  254.192933]   ksys_write+0x5a/0xd0
<4>[  254.192949]   do_syscall_64+0x33/0x80
<4>[  254.192965]   entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.192986] irq event stamp: 43775
<4>[  254.192994] hardirqs last  enabled at (43775): [<ffffffff81c00c42>] asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193023] hardirqs last disabled at (43774): [<ffffffff81aa691a>] sysvec_apic_timer_interrupt+0xa/0xb0
<4>[  254.193049] softirqs last  enabled at (42548): [<ffffffff81e00342>] __do_softirq+0x342/0x48e
<4>[  254.193074] softirqs last disabled at (42543): [<ffffffff810b45fd>] irq_exit_rcu+0xad/0xd0
<4>[  254.193101]
                  other info that might help us debug this:
<4>[  254.193107]  Possible unsafe locking scenario:

<4>[  254.193112]        CPU0
<4>[  254.193117]        ----
<4>[  254.193121]   lock(rtc_lock);
<4>[  254.193137]   <Interrupt>
<4>[  254.193142]     lock(rtc_lock);
<4>[  254.193156]
                   *** DEADLOCK ***

<4>[  254.193161] 6 locks held by rtcwake/5309:
<4>[  254.193174]  #0: ffff888104861430 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x5a/0xd0
<4>[  254.193232]  #1: ffff88810f823288 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xe7/0x1c0
<4>[  254.193282]  #2: ffff888100cef3c0 (kn->active#285
<7>[  254.192706] i915 0000:00:02.0: [drm:intel_modeset_setup_hw_state [i915]] [CRTC:51:pipe A] hw state readout: disabled
<4>[  254.193307] ){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xf0/0x1c0
<4>[  254.193333]  #3: ffffffff82649fa8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend.cold.8+0xce/0x34a
<4>[  254.193387]  #4: ffffffff827a2108 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x47/0x70
<4>[  254.193433]  #5: ffff8881019ea178 (&dev->mutex){....}-{3:3}, at: device_resume+0x68/0x1e0
<4>[  254.193485]
                  stack backtrace:
<4>[  254.193492] CPU: 1 PID: 5309 Comm: rtcwake Not tainted 5.12.0-rc1-CI-CI_DRM_9834+ #1
<4>[  254.193514] Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019
<4>[  254.193524] Call Trace:
<4>[  254.193536]  dump_stack+0x7f/0xad
<4>[  254.193567]  mark_lock.part.47+0x8ca/0xce0
<4>[  254.193604]  __lock_acquire+0x39b/0x2590
<4>[  254.193626]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193660]  lock_acquire+0xd1/0x3d0
<4>[  254.193677]  ? cmos_interrupt+0x18/0x100
<4>[  254.193716]  _raw_spin_lock+0x2a/0x40
<4>[  254.193735]  ? cmos_interrupt+0x18/0x100
<4>[  254.193758]  cmos_interrupt+0x18/0x100
<4>[  254.193785]  cmos_resume+0x2ac/0x2d0
<4>[  254.193813]  ? acpi_pm_set_device_wakeup+0x1f/0x110
<4>[  254.193842]  ? pnp_bus_suspend+0x10/0x10
<4>[  254.193864]  pnp_bus_resume+0x5e/0x90
<4>[  254.193885]  dpm_run_callback+0x5f/0x240
<4>[  254.193914]  device_resume+0xb2/0x1e0
<4>[  254.193942]  ? pm_dev_err+0x25/0x25
<4>[  254.193974]  dpm_resume+0xea/0x3f0
<4>[  254.194005]  dpm_resume_end+0x8/0x10
<4>[  254.194030]  suspend_devices_and_enter+0x29b/0xaa0
<4>[  254.194066]  pm_suspend.cold.8+0x301/0x34a
<4>[  254.194094]  state_store+0x7b/0xe0
<4>[  254.194124]  kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.194151]  new_sync_write+0x11d/0x1b0
<4>[  254.194183]  vfs_write+0x265/0x390
<4>[  254.194207]  ksys_write+0x5a/0xd0
<4>[  254.194232]  do_syscall_64+0x33/0x80
<4>[  254.194251]  entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.194274] RIP: 0033:0x7f07d79691e7
<4>[  254.194293] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
<4>[  254.194312] RSP: 002b:00007ffd9cc2c768 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[  254.194337] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f07d79691e7
<4>[  254.194352] RDX: 0000000000000004 RSI: 0000556ebfc63590 RDI: 000000000000000b
<4>[  254.194366] RBP: 0000556ebfc63590 R08: 0000000000000000 R09: 0000000000000004
<4>[  254.194379] R10: 0000556ebf0ec2a6 R11: 0000000000000246 R12: 0000000000000004

which breaks S3-resume on fi-kbl-soraka presumably as that's slow enough
to trigger the alarm during the suspend.

Fixes: 6950d046eb6e ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
References: 66e4f4a9cc ("rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()"):
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Xiaofei Tan <tanxiaofei@huawei.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210305122140.28774-1-chris@chris-wilson.co.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:59 +01:00
Thomas Gleixner
db44a9443e rtc: mc146818: Reduce spinlock section in mc146818_set_time()
[ Upstream commit dcf257e92622ba0e25fdc4b6699683e7ae67e2a1 ]

No need to hold the lock and disable interrupts for doing math.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.709243630@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Xiaofei Tan
17293d630f rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
[ Upstream commit 6950d046eb6eabbc271fda416460c05f7a85698a ]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1612355981-6764-2-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
acfd8ef683 rtc: cmos: avoid UIP when reading alarm time
[ Upstream commit cdedc45c579faf8cc6608d3ef81576ee0d512aa4 ]

Some Intel chipsets disconnect the time and date RTC registers when the
clock update is in progress: during this time reads may return bogus
values and writes fail silently. This includes the RTC alarm registers.
[1]

cmos_read_alarm() did not take account for that, which caused alarm time
reads to sometimes return bogus values. This can be shown with a test
patch that I am attaching to this patch series.

Fix this, by using mc146818_avoid_UIP().

[1] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...]
Datasheet, Volume 1 of 2 (Intel's Document Number: 334658-006)
Page 208
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf
        "If a RAM read from the ten time and date bytes is attempted
        during an update cycle, the value read do not necessarily
        represent the true contents of those locations. Any RAM writes
        under the same conditions are ignored."

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-9-mat.jonczyk@o2.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
949bae0282 rtc: cmos: avoid UIP when writing alarm time
[ Upstream commit cd17420ebea580c22dd3a93f7237de3d2cfafc37 ]

Some Intel chipsets disconnect the time and date RTC registers when the
clock update is in progress: during this time reads may return bogus
values and writes fail silently. This includes the RTC alarm registers.
[1]

cmos_set_alarm() did not take account for that, fix it.

[1] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...]
Datasheet, Volume 1 of 2 (Intel's Document Number: 334658-006)
Page 208
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf
        "If a RAM read from the ten time and date bytes is attempted
        during an update cycle, the value read do not necessarily
        represent the true contents of those locations. Any RAM writes
        under the same conditions are ignored."

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-10-mat.jonczyk@o2.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
33ac73a41a rtc: mc146818-lib: extract mc146818_avoid_UIP
[ Upstream commit ec5895c0f2d87b9bf4185db1915e40fa6fcfc0ac ]

Function mc146818_get_time() contains an elaborate mechanism of reading
the RTC time while no RTC update is in progress. It turns out that
reading the RTC alarm clock also requires avoiding the RTC update.
Therefore, the mechanism in mc146818_get_time() should be reused - so
extract it into a separate function.

The logic in mc146818_avoid_UIP() is same as in mc146818_get_time()
except that after every

        if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) {

there is now "mdelay(1)".

To avoid producing a very unreadable patch, mc146818_get_time() will be
refactored to use mc146818_avoid_UIP() in the next patch.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-6-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
8bb5fe5830 rtc: mc146818-lib: fix RTC presence check
[ Upstream commit ea6fa4961aab8f90a8aa03575a98b4bda368d4b6 ]

To prevent an infinite loop in mc146818_get_time(),
commit 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs")
added a check for RTC availability. Together with a later fix, it
checked if bit 6 in register 0x0d is cleared.

This, however, caused a false negative on a motherboard with an AMD
SB710 southbridge; according to the specification [1], bit 6 of register
0x0d of this chipset is a scratchbit. This caused a regression in Linux
5.11 - the RTC was determined broken by the kernel and not used by
rtc-cmos.c [3]. This problem was also reported in Fedora [4].

As a better alternative, check whether the UIP ("Update-in-progress")
bit is set for longer then 10ms. If that is the case, then apparently
the RTC is either absent (and all register reads return 0xff) or broken.
Also limit the number of loop iterations in mc146818_get_time() to 10 to
prevent an infinite loop there.

The functions mc146818_get_time() and mc146818_does_rtc_work() will be
refactored later in this patch series, in order to fix a separate
problem with reading / setting the RTC alarm time. This is done so to
avoid a confusion about what is being fixed when.

In a previous approach to this problem, I implemented a check whether
the RTC_HOURS register contains a value <= 24. This, however, sometimes
did not work correctly on my Intel Kaby Lake laptop. According to
Intel's documentation [2], "the time and date RAM locations (0-9) are
disconnected from the external bus" during the update cycle so reading
this register without checking the UIP bit is incorrect.

[1] AMD SB700/710/750 Register Reference Guide, page 308,
https://developer.amd.com/wordpress/media/2012/10/43009_sb7xx_rrg_pub_1.00.pdf

[2] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...] Datasheet
Volume 1 of 2, page 209
Intel's Document Number: 334658-006,
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf

[3] Functions in arch/x86/kernel/rtc.c apparently were using it.

[4] https://bugzilla.redhat.com/show_bug.cgi?id=1936688

Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs")
Fixes: ebb22a059436 ("rtc: mc146818: Dont test for bit 0-5 in Register D")
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-5-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
775d4661f1 rtc: Check return value from mc146818_get_time()
[ Upstream commit 0dd8d6cb9eddfe637bcd821bbfd40ebd5a0737b9 ]

There are 4 users of mc146818_get_time() and none of them was checking
the return value from this function. Change this.

Print the appropriate warnings in callers of mc146818_get_time() instead
of in the function mc146818_get_time() itself, in order not to add
strings to rtc-mc146818-lib.c, which is kind of a library.

The callers of alpha_rtc_read_time() and cmos_read_time() may use the
contents of (struct rtc_time *) even when the functions return a failure
code. Therefore, set the contents of (struct rtc_time *) to 0x00,
which looks more sensible then 0xff and aligns with the (possibly
stale?) comment in cmos_read_time:

	/*
	 * If pm_trace abused the RTC for storage, set the timespec to 0,
	 * which tells the caller that this RTC value is unusable.
	 */

For consistency, do this in mc146818_get_time().

Note: hpet_rtc_interrupt() may call mc146818_get_time() many times a
second. It is very unlikely, though, that the RTC suddenly stops
working and mc146818_get_time() would consistently fail.

Only compile-tested on alpha.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-alpha@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-4-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Mateusz Jończyk
b9a5c470e0 rtc: mc146818-lib: change return values of mc146818_get_time()
[ Upstream commit d35786b3a28dee20b12962ae2dd365892a99ed1a ]

No function is checking mc146818_get_time() return values yet, so
correct them to make them more customary.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-3-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Mateusz Jończyk
94eaf9966e rtc: cmos: remove stale REVISIT comments
[ Upstream commit e1aba37569f0aa9c993f740828871e48eea79f98 ]

It appears mc146818_get_time() and mc146818_set_time() now correctly
use the century register as specified in the ACPI FADT table. It is not
clear what else could be done here.

These comments were introduced by
        commit 7be2c7c96a ("[PATCH] RTC framework driver for CMOS RTCs")
in 2007, which originally referenced function get_rtc_time() in
include/asm-generic/rtc.h .

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210716210437.29622-1-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Thomas Gleixner
f5b51f8550 rtc: mc146818: Dont test for bit 0-5 in Register D
[ Upstream commit ebb22a05943666155e6da04407cc6e913974c78c ]

The recent change to validate the RTC turned out to be overly tight.

While it cures the problem on the reporters machine it breaks machines
with Intel chipsets which use bit 0-5 of the D register. So check only
for bit 6 being 0 which is the case on these Intel machines as well.

Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs")
Reported-by: Serge Belyshev <belyshev@depni.sinp.msu.ru>
Reported-by: Dirk Gouders <dirk@gouders.net>
Reported-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Dirk Gouders <dirk@gouders.net>
Tested-by: Len Brown <len.brown@intel.com>
Tested-by: Borislav Petkov <bp@suse.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/87zh0nbnha.fsf@nanos.tec.linutronix.de
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Thomas Gleixner
3736972360 rtc: mc146818: Detect and handle broken RTCs
[ Upstream commit 211e5db19d15a721b2953ea54b8f26c2963720eb ]

The recent fix for handling the UIP bit unearthed another issue in the RTC
code. If the RTC is advertised but the readout is straight 0xFF because
it's not available, the old code just proceeded with crappy values, but the
new code hangs because it waits for the UIP bit to become low.

Add a sanity check in the RTC CMOS probe function which reads the RTC_VALID
register (Register D) which should have bit 0-6 cleared. If that's not the
case then fail to register the CMOS.

Add the same check to mc146818_get_time(), warn once when the condition
is true and invalidate the rtc_time data.

Reported-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/87tur3fx7w.fsf@nanos.tec.linutronix.de
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Thomas Gleixner
7c7075c88d rtc: mc146818: Prevent reading garbage
[ Upstream commit 05a0302c35481e9b47fb90ba40922b0a4cae40d8 ]

The MC146818 driver is prone to read garbage from the RTC. There are
several issues all related to the update cycle of the MC146818. The chip
increments seconds obviously once per second and indicates that by a bit in
a register. The bit goes high 244us before the actual update starts. During
the update the readout of the time values is undefined.

The code just checks whether the update in progress bit (UIP) is set before
reading the clock. If it's set it waits arbitrary 20ms before retrying,
which is ample because the maximum update time is ~2ms.

But this check does not guarantee that the UIP bit goes high and the actual
update happens during the readout. So the following can happen

 0.997 	       UIP = False
   -> Interrupt/NMI/preemption
 0.998	       UIP -> True
 0.999	       Readout	<- Undefined

To prevent this rework the code so it checks UIP before and after the
readout and if set after the readout try again.

But that's not enough to cover the following:

 0.997 	       UIP = False
 	       Readout seconds
   -> NMI (or vCPU scheduled out)
 0.998	       UIP -> True
 	       update completes
	       UIP -> False
 1.000	       Readout	minutes,....
 	       UIP check succeeds

That can make the readout wrong up to 59 seconds.

To prevent this, read the seconds value before the first UIP check,
validate it after checking UIP and after reading out the rest.

It's amazing that the original i386 code had this actually correct and
the generic implementation of the MC146818 driver got it wrong in 2002 and
it stayed that way until today.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.594826678@linutronix.de
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Yang Yingliang
82bfea344e rtc: mt6397: check return value after calling platform_get_resource()
[ Upstream commit d3b43eb505bffb8e4cdf6800c15660c001553fe6 ]

It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.

Fixes: fc2979118f ("rtc: mediatek: Add MT6397 RTC driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220505125043.1594771-1-yangyingliang@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:32:33 +02:00
Mario Limonciello
00d8b06a4e rtc: mc146818-lib: Fix the AltCentury for AMD platforms
[ Upstream commit 3ae8fd41573af4fb3a490c9ed947fc936ba87190 ]

Setting the century forward has been failing on AMD platforms.
There was a previous attempt at fixing this for family 0x17 as part of
commit 7ad295d519 ("rtc: Fix the AltCentury value on AMD/Hygon
platform") but this was later reverted due to some problems reported
that appeared to stem from an FW bug on a family 0x17 desktop system.

The same comments mentioned in the previous commit continue to apply
to the newer platforms as well.

```
MC146818 driver use function mc146818_set_time() to set register
RTC_FREQ_SELECT(RTC_REG_A)'s bit4-bit6 field which means divider stage
reset value on Intel platform to 0x7.

While AMD/Hygon RTC_REG_A(0Ah)'s bit4 is defined as DV0 [Reference]:
DV0 = 0 selects Bank 0, DV0 = 1 selects Bank 1. Bit5-bit6 is defined
as reserved.

DV0 is set to 1, it will select Bank 1, which will disable AltCentury
register(0x32) access. As UEFI pass acpi_gbl_FADT.century 0x32
(AltCentury), the CMOS write will be failed on code:
CMOS_WRITE(century, acpi_gbl_FADT.century).

Correct RTC_REG_A bank select bit(DV0) to 0 on AMD/Hygon CPUs, it will
enable AltCentury(0x32) register writing and finally setup century as
expected.
```

However in closer examination the change previously submitted was also
modifying bits 5 & 6 which are declared reserved in the AMD documentation.
So instead modify just the DV0 bank selection bit.

Being cognizant that there was a failure reported before, split the code
change out to a static function that can also be used for exclusions if
any regressions such as Mikhail's pop up again.

Cc: Jinke Fan <fanjinke@hygon.cn>
Cc: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Link: https://lore.kernel.org/all/CABXGCsMLob0DC25JS8wwAYydnDoHBSoMh2_YLPfqm3TTvDE-Zw@mail.gmail.com/
Link: https://www.amd.com/system/files/TechDocs/51192_Bolton_FCH_RRG.pdf
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220111225750.1699-1-mario.limonciello@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:54 +02:00
Andre Przywara
703c80ff43 rtc: sun6i: Fix time overflow handling
[ Upstream commit 9f6cd82eca7e91a0d0311242a87c6aa3c2737968 ]

Using "unsigned long" for UNIX timestamps is never a good idea, and
comparing the value of such a variable against U32_MAX does not do
anything useful on 32-bit systems.

Use the proper time64_t type when dealing with timestamps, and avoid
cutting down the time range unnecessarily. This also fixes the flawed
check for the alarm time being too far into the future.

The check for this condition is actually somewhat theoretical, as the
RTC counts till 2033 only anyways, and 2^32 seconds from now is not
before the year 2157 - at which point I hope nobody will be using this
hardware anymore.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220211122643.1343315-4-andre.przywara@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:53 +02:00
Hugo Villeneuve
c39b91fcd5 rtc: pcf2127: fix bug when reading alarm registers
[ Upstream commit 73ce05302007eece23a6acb7dc124c92a2209087 ]

The first bug is that reading the 5 alarm registers results in a read
operation of 20 bytes. The reason is because the destination buffer is
defined as an array of "unsigned int", and we use the sizeof()
operator on this array to define the bulk read count.

The second bug is that the read value is invalid, because we are
indexing the destination buffer as integers (4 bytes), instead of
indexing it as u8.

Changing the destination buffer type to u8 fixes both problems.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220208162908.3182581-1-hugo@hugovil.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:52 +02:00
Vincent Whitchurch
2b4e5a2d7d rtc: fix use-after-free on device removal
[ Upstream commit c8fa17d9f08a448184f03d352145099b5beb618e ]

If the irqwork is still scheduled or running while the RTC device is
removed, a use-after-free occurs in rtc_timer_do_work().  Cleanup the
timerqueue and ensure the work is stopped to fix this.

 BUG: KASAN: use-after-free in mutex_lock+0x94/0x110
 Write of size 8 at addr ffffff801d846338 by task kworker/3:1/41

 Workqueue: events rtc_timer_do_work
 Call trace:
  mutex_lock+0x94/0x110
  rtc_timer_do_work+0xec/0x630
  process_one_work+0x5fc/0x1344
  ...

 Allocated by task 551:
  kmem_cache_alloc_trace+0x384/0x6e0
  devm_rtc_allocate_device+0xf0/0x574
  devm_rtc_device_register+0x2c/0x12c
  ...

 Freed by task 572:
  kfree+0x114/0x4d0
  rtc_device_release+0x64/0x80
  device_release+0x8c/0x1f4
  kobject_put+0x1c4/0x4b0
  put_device+0x20/0x30
  devm_rtc_release_device+0x1c/0x30
  devm_action_release+0x54/0x90
  release_nodes+0x124/0x310
  devres_release_group+0x170/0x240
  i2c_device_remove+0xd8/0x314
  ...

 Last potentially related work creation:
  insert_work+0x5c/0x330
  queue_work_on+0xcc/0x154
  rtc_set_time+0x188/0x5bc
  rtc_dev_ioctl+0x2ac/0xbd0
  ...

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210160951.7718-1-vincent.whitchurch@axis.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:52 +02:00
Jiasheng Jiang
2e52a29470 rtc: wm8350: Handle error for wm8350_register_irq
[ Upstream commit 43f0269b6b89c1eec4ef83c48035608f4dcdd886 ]

As the potential failure of the wm8350_register_irq(),
it should be better to check it and return error if fails.
Also, it need not free 'wm_rtc->rtc' since it will be freed
automatically.

Fixes: 077eaf5b40 ("rtc: rtc-wm8350: add support for WM8350 RTC")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220303085030.291793-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13 21:00:54 +02:00
Tom Rix
33c204266c rtc: check if __rtc_read_time was successful
commit 915593a7a663b2ad08b895a5f3ba8b19d89d4ebf upstream.

Clang static analysis reports this issue
interface.c:810:8: warning: Passed-by-value struct
  argument contains uninitialized data
  now = rtc_tm_to_ktime(tm);
      ^~~~~~~~~~~~~~~~~~~

tm is set by a successful call to __rtc_read_time()
but its return status is not checked.  Check if
it was successful before setting the enabled flag.
Move the decl of err to function scope.

Fixes: 2b2f5ff00f ("rtc: interface: ignore expired timers when enqueuing new timers")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220326194236.2916310-1-trix@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:40:40 +02:00
Uwe Kleine-König
e4c777fd8c amba: Make the remove callback return void
[ Upstream commit 3fd269e74f2feec973f45ee11d822faeda4fe284 ]

All amba drivers return 0 in their remove callback. Together with the
driver core ignoring the return value anyhow, it doesn't make sense to
return a value here.

Change the remove prototype to return void, which makes it explicit that
returning an error value doesn't work as expected. This simplifies changing
the core remove callback to return void, too.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org> # for drivers/memory
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> # for hwtracing/coresight
Acked-By: Vinod Koul <vkoul@kernel.org> # for dmaengine
Acked-by: Guenter Roeck <linux@roeck-us.net> # for watchdog
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Takashi Iwai <tiwai@suse.de> # for sound
Acked-by: Vladimir Zapolskiy <vz@mleia.com> # for memory/pl172
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210126165835.687514-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:02 +02:00
Riwen Lu
460aa9d873 rtc: cmos: Evaluate century appropriate
commit ff164ae39b82ee483b24579c8e22a13a8ce5bd04 upstream.

There's limiting the year to 2069. When setting the rtc year to 2070,
reading it returns 1970. Evaluate century starting from 19 to count the
correct year.

$ sudo date -s 20700106
Mon 06 Jan 2070 12:00:00 AM CST
$ sudo hwclock -w
$ sudo hwclock -r
1970-01-06 12:00:49.604968+08:00

Fixes: 2a4daadd4d ("rtc: cmos: ignore bogus century byte")

Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
Acked-by: Eric Wong <e@80x24.org>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220106084609.1223688-1-luriwen@kylinos.cn
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> # preparation for stable
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08 18:30:39 +01:00
Laurence de Bruxelles
c736ec01a2 rtc: pxa: fix null pointer dereference
commit 34127b3632b21e5c391756e724b1198eb9917981 upstream.

With the latest stable kernel versions the rtc on the PXA based
Zaurus does not work, when booting I see the following kernel messages:

pxa-rtc pxa-rtc: failed to find rtc clock source
pxa-rtc pxa-rtc: Unable to init SA1100 RTC sub-device
pxa-rtc: probe of pxa-rtc failed with error -2
hctosys: unable to open rtc device (rtc0)

I think this is because commit f2997775b1 ("rtc: sa1100: fix possible
race condition") moved the allocation of the rtc_device struct out of
sa1100_rtc_init and into sa1100_rtc_probe. This means that pxa_rtc_probe
also needs to do allocation for the rtc_device struct, otherwise
sa1100_rtc_init will try to dereference a null pointer. This patch adds
that allocation by copying how sa1100_rtc_probe in
drivers/rtc/rtc-sa1100.c does it; after the IRQs are set up a managed
rtc_device is allocated.

I've tested this patch with `qemu-system-arm -machine akita` and with a
real Zaurus SL-C1000 applied to 4.19, 5.4, and 5.10.

Signed-off-by: Laurence de Bruxelles <lfdebrux@gmail.com>
Fixes: f2997775b1 ("rtc: sa1100: fix possible race condition")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220101154149.12026-1-lfdebrux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 10:54:33 +01:00
Mateusz Jończyk
1da0b1cd42 rtc: cmos: take rtc_lock while reading from CMOS
commit 454f47ff464325223129b9b5b8d0b61946ec704d upstream.

Reading from the CMOS involves writing to the index register and then
reading from the data register. Therefore access to the CMOS has to be
serialized with rtc_lock. This invocation of CMOS_READ was not
serialized, which could cause trouble when other code is accessing CMOS
at the same time.

Use spin_lock_irq() like the rest of the function.

Nothing in kernel modifies the RTC_DM_BINARY bit, so there could be a
separate pair of spin_lock_irq() / spin_unlock_irq() before doing the
math.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-2-mat.jonczyk@o2.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 10:53:42 +01:00
Dan Carpenter
038dfd67d3 rtc: rv3032: fix error handling in rv3032_clkout_set_rate()
[ Upstream commit c3336b8ac6091df60a5c1049a8c685d0b947cc61 ]

Do not call rv3032_exit_eerd() if the enter function fails but don't
forget to call the exit when the enter succeeds.

Fixes: 2eeaa532ac ("rtc: rv3032: Add a driver for Microcrystal RV-3032")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211012101028.GT2083@kadam
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:23 +01:00
Yu-Tung Chang
647c19bc61 rtc: rx8010: select REGMAP_I2C
[ Upstream commit 0c45d3e24ef3d3d87c5e0077b8f38d1372af7176 ]

The rtc-rx8010 uses the I2C regmap but doesn't select it in Kconfig so
depending on the configuration the build may fail. Fix it.

Signed-off-by: Yu-Tung Chang <mtwget@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210830052532.40356-1-mtwget@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:09:02 +02:00
Dmitry Osipenko
ebedb252a4 rtc: tps65910: Correct driver module alias
commit 8d448fa0a8bb1c8d94eef7647edffe9ac81a281e upstream.

The TPS65910 RTC driver module doesn't auto-load because of the wrong
module alias that doesn't match the device name, fix it.

Cc: stable@vger.kernel.org
Reported-by: Anton Bambura <jenneron@protonmail.com>
Tested-by: Anton Bambura <jenneron@protonmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210808160030.8556-1-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18 13:40:05 +02:00
Krzysztof Kozlowski
cdb995a6cb rtc: max77686: Do not enforce (incorrect) interrupt trigger type
[ Upstream commit 742b0d7e15c333303daad4856de0764f4bc83601 ]

Interrupt line can be configured on different hardware in different way,
even inverted.  Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.

The Maxim 77686 datasheet describes the interrupt line as active low
with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.

The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races.  With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210526172036.183223-6-krzysztof.kozlowski@canonical.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-25 14:36:16 +02:00