No platforms are currently setting no_irq. Anyway, letting platform_get_irq
fail is fine as this means that there is no IRQ. In that case, clear
RTC_FEATURE_ALARM so the core knows there are no alarms.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220309162301.61679-2-alexandre.belloni@bootlin.com
H6 supports IOSC calibration and an ext-osc32k input. Unlike newer SoCs,
it has a single parent for its fanout clock.
Add support for H6 in the CCU driver, replacing the support in the
existing early OF clock provider.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220203021736.13434-7-samuel@sholland.org
The RTC power domain in sun6i and newer SoCs manages the 16 MHz RC
oscillator (called "IOSC" or "osc16M") and the optional 32 kHz crystal
oscillator (called "LOSC" or "osc32k"). Starting with the H6, this power
domain also handles the 24 MHz DCXO (called variously "HOSC", "dcxo24M",
or "osc24M") as well. The H6 also adds a calibration circuit for IOSC.
Later SoCs introduce further variations on the design:
- H616 adds an additional mux for the 32 kHz fanout source.
- R329 adds an additional mux for the RTC timekeeping clock, a clock
for the SPI bus between power domains inside the RTC, and removes the
IOSC calibration functionality.
Take advantage of the CCU framework to handle this increased complexity.
This driver is intended to be a drop-in replacement for the existing RTC
clock provider. So some runtime adjustment of the clock parents is
needed, both to handle hardware differences, and to support the old
binding which omitted some of the input clocks.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220203021736.13434-6-samuel@sholland.org
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
The H616 RTC changes its day storage to the newly introduced linear day
scheme, so pair the new compatible string with this feature flag.
The RTC clock parts are handled in a separate driver now, so we skip
the clock parts in this driver completely.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220211122643.1343315-7-andre.przywara@arm.com
Newer versions of the Allwinner RTC, for instance as found in the H616
SoC, not only store the current day as a linear number, but also change
the way the alarm is handled: There are now two registers, that
explicitly store the wakeup time, in the same format as the current
time.
Add support for that variant by writing the requested wakeup time
directly into the registers, instead of programming the seconds left, as
the old SoCs required.
Reviewed by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220211122643.1343315-6-andre.przywara@arm.com
Newer versions of the Allwinner RTC, as for instance found in the H616
SoC, no longer store a broken-down day/month/year representation in the
RTC_DAY_REG, but just a linear day number.
The user manual does not give any indication about the expected epoch
time of this day count, but the BSP kernel uses the UNIX epoch, which
allows easy support due to existing conversion functions in the kernel.
Allow tagging a compatible string with a flag, and use that to mark
those new RTCs. Then convert between a UNIX day number (converted into
seconds) and the broken-down day representation using mktime64() and
time64_to_tm() in the set_time/get_time functions.
That enables support for the RTC in those new chips.
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/20220211122643.1343315-5-andre.przywara@arm.com
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
When there is no interrupt line, rtc alarm feature is disabled.
The clearing of the alarm feature bit was being done prior to allocations
of ldata->rtc device, resulting in a null pointer dereference.
Clear RTC_FEATURE_ALARM after the rtc device is allocated.
Fixes: d9b0dd54a1 ("rtc: pl031: use RTC_FEATURE_ALARM")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Pouladi <quic_apouladi@quicinc.com>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220225161924.274141-1-quic_eberman@quicinc.com
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: dcf257e926 ("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
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
If the interrupt pin of the PCF2127 is routed to the input of a GPIO
expander using the pca953x driver, the later will only accept an IRQ
of type IRQ_TYPE_EDGE_FALLING or IRQ_TYPE_EDGE_RISING, and the IRQ
request will fail.
Therefore, allow the IRQ type to be passed from the device tree data
if available.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220117225742.1252362-1-hugo@hugovil.com
When building with automatic stack variable initialization, GCC 12
complains about variables defined outside of switch case statements.
Move variables outside the switch, which silences warnings:
./drivers/rtc/rtc-pcf8523.c:284:20: error: statement will never be executed [-Werror=switch-unreachable]
284 | u8 mode;
|
./drivers/rtc/rtc-pcf8523.c:245:21: error: statement will never be executed [-Werror=switch-unreachable]
245 | u32 value;
| ^~~~~
Signed-off-by: Victor Erminpour <victor.erminpour@oracle.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1644453027-886-1-git-send-email-victor.erminpour@oracle.com
H6 and newer variants of the RTC hardware have a bus clock gate in the
PRCM CCU. This was not known at the time H6 support was added, so it was
not included in the H6 RTC binding, nor in the H6 PRCM CCU driver. Now
that this clock gate is documented, it is included in the A100 and D1
PRCM CCU drivers. Therefore, the RTC driver needs to have a consumer for
the clock gate to prevent Linux from disabling it.
Patch-changes: 3
- New patch for compatibility with new CCU drivers
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220203021736.13434-4-samuel@sholland.org
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
If devm_ioremap_resource() fails, it should return error
code from sp_rtc->reg_base in sp_rtc_probe().
Fixes: fad6cbe9b2 ("rtc: Add driver for RTC in Sunplus SP7021")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220106075711.3216468-1-yangyingliang@huawei.com
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
The devm_kzalloc() function returns NULL on error, it doesn't return
error pointers.
Fixes: 86559400b3 ("rtc: gamecube: Add a RTC driver for the GameCube, Wii and Wii U")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220107073340.GF22086@kili
The mc146818_get_time() function returns zero on success or negative
a error code on failure. It needs to be type int.
Fixes: d35786b3a2 ("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
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
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.
In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211220011524.17206-1-prabhakar.mahadev-lad.rj@bp.renesas.com
When building with automatic stack variable initialization, GCC 12
complains about variables defined outside of switch case statements.
Move the variable into the case that uses it, which silences the warning:
drivers/rtc/dev.c: In function 'rtc_dev_ioctl':
drivers/rtc/dev.c:394:30: warning: statement will never be executed [-Wswitch-unreachable]
394 | long offset;
| ^~~~~~
Fixes: 6a8af1b656 ("rtc: add parameter ioctl")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211209043915.1378393-1-keescook@chromium.org
The XSL bit only exists in RS5C372A/B. On other Ricoh RTC chips
supported in rs5c372, this bit has different meaning. For example, on
R2221x and R2223x, this bit of oscillation adjustment register
determines the operation frequency of oscillation adjustment circuit and
the oscillation is always 32768HZ. But rs5c372_get_trim gives 32000HZ to
osc when DEV is 1.
Signed-off-by: Camel Guo <camelg@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211206125832.6461-1-camel.guo@axis.com
In order for linux userspace application to be able to adjust offset to
keep rtc precision as high as possible, this commit adds support of
offset correction by adjusting the time trimming register on
rs5c372[a|b] and oscilluation adjustment register on r2025x, r222[1|3]x,
rv5c38[6|7]a.
Signed-off-by: Camel Guo <camelg@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211202152252.31264-1-camel.guo@axis.com
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
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
Refactor mc146818_does_rtc_work() so that it uses mc146818_avoid_UIP().
It is enough to call mc146818_avoid_UIP() with no callback.
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/20211210200131.153887-8-mat.jonczyk@o2.pl
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
To prevent an infinite loop in mc146818_get_time(),
commit 211e5db19d ("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: 211e5db19d ("rtc: mc146818: Detect and handle broken RTCs")
Fixes: ebb22a0594 ("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
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
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
Alexandre Belloni
Samuel Holland
Jiasheng Jiang
Andre Przywara
Ali Pouladi
Mateusz Jończyk
Hugo Villeneuve
Victor Erminpour
Vincent Whitchurch
Yang Yingliang
Riwen Lu
Dan Carpenter
Laurence de Bruxelles
Lad Prabhakar
Kees Cook
Vincent Shih
Camel Guo