linux.git/drivers/rtc/interface.c, branch v6.1.154

rtc: check if __rtc_read_time was successful in rtc_timer_do_work()

2024-12-14T18:54:07+00:00

[ Upstream commit e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d ]

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

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

Fixes: 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events")
Signed-off-by: Yongliang Gao 
Acked-by: Jingqun Li 
Link: https://lore.kernel.org/r/20241011043153.3788112-1-leonylgao@gmail.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: interface: Add RTC offset to alarm after fix-up

2024-08-03T06:49:28+00:00

[ Upstream commit 463927a8902a9f22c3633960119410f57d4c8920 ]

`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: fd6792bb022e ("rtc: fix alarm read and set offset")

Signed-off-by: Csókás, Bence 
Link: https://lore.kernel.org/r/20240619140451.2800578-1-csokas.bence@prolan.hu
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: allow rtc_read_alarm without read_alarm callback

2023-03-11T12:55:30+00:00

[ Upstream commit a783c962619271a8b905efad1d89adfec11ae0c8 ]

.read_alarm is not necessary to read the current alarm because it is
recorded in the aie_timer and so rtc_read_alarm() will never call
rtc_read_alarm_internal() which is the only function calling the callback.

Reported-by: Zhipeng Wang 
Reported-by: Marcel Ziswiler 
Fixes: 7ae41220ef58 ("rtc: introduce features bitfield")
Tested-by: Philippe Schenker 
Link: https://lore.kernel.org/r/20230214222754.582582-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: check if __rtc_read_time was successful

2022-03-29T20:45:50+00:00

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: 2b2f5ff00f63 ("rtc: interface: ignore expired timers when enqueuing new timers")
Signed-off-by: Tom Rix 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20220326194236.2916310-1-trix@redhat.com

rtc: handle alarms with a minute resolution

2021-11-09T23:45:56+00:00

Handle alarms with a minute resolution in the core. Until now drivers have
been open coding the seconds part removal and have been doing that wrongly.
Most of them are rounding up which means the allow the system to miss
deadlines. So, round down and let __rtc_set_alarm return immediately if the
time has already passed.

Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20211107225458.111068-1-alexandre.belloni@bootlin.com

rtc: expose RTC_FEATURE_UPDATE_INTERRUPT

2021-10-18T15:25:52+00:00

Set RTC_FEATURE_UPDATE_INTERRUPT by default and clear it when it is not
supported.

Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20211018152337.78732-1-alexandre.belloni@bootlin.com

rtc: rtc_update_irq_enable: rework UIE emulation

2021-04-29T21:04:13+00:00

Now that the core is aware of whether alarms are available, it is possible
to decide whether UIE emulation is required before actually trying to set
the alarm.

This greatly simplifies rtc_update_irq_enable because there is now only one
error value to track and is not relying on the return value of
__rtc_set_alarm anymore.

Tested-by: Łukasz Stelmach 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210418000023.995758-3-alexandre.belloni@bootlin.com

rtc: introduce features bitfield

2021-01-16T22:19:26+00:00

Introduce a bitfield to allow the drivers to announce the available
features for an RTC.

The main use case would be to better handle alarms, that could be present
or not or have a minute resolution or may need a correct week day to be set.

Use the newly introduced RTC_FEATURE_ALARM bit to then test whether alarms
are available instead of relying on the presence of ops->set_alarm.

Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210110231752.1418816-2-alexandre.belloni@bootlin.com

rtc: interface: fix kerneldoc comments

2019-11-27T08:31:08+00:00

Fix kerneldoc warnings:

drivers/rtc/interface.c:619: warning: Function parameter or member 'num' not described in 'rtc_handle_legacy_irq'
drivers/rtc/interface.c:619: warning: Function parameter or member 'mode' not described in 'rtc_handle_legacy_irq'
drivers/rtc/interface.c:804: warning: Function parameter or member 'rtc' not described in 'rtc_timer_enqueue'
drivers/rtc/interface.c:804: warning: Function parameter or member 'timer' not described in 'rtc_timer_enqueue'
drivers/rtc/interface.c:864: warning: Function parameter or member 'rtc' not described in 'rtc_timer_remove'
drivers/rtc/interface.c:864: warning: Function parameter or member 'timer' not described in 'rtc_timer_remove'
drivers/rtc/interface.c:900: warning: Function parameter or member 'work' not described in 'rtc_timer_do_work'
drivers/rtc/interface.c:1035: warning: Function parameter or member 'rtc' not described in 'rtc_read_offset'
drivers/rtc/interface.c:1035: warning: Function parameter or member 'offset' not described in 'rtc_read_offset'
drivers/rtc/interface.c:1070: warning: Function parameter or member 'rtc' not described in 'rtc_set_offset'
drivers/rtc/interface.c:1070: warning: Function parameter or member 'offset' not described in 'rtc_set_offset'

Link: https://lore.kernel.org/r/20191127082932.666869-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni

rtc: disallow update interrupts when time is invalid

2019-11-08T15:14:09+00:00

Never enable update interrupts when the time set on the rtc is invalid.
In that case, also avoid enabling the emulation because it will fail for
the same reason.

Link: https://lore.kernel.org/r/20191021155631.3342-2-alexandre.belloni@bootlin.com
Link: https://lore.kernel.org/r/CA+ASDXMarBG5C1Kz42B9i_iVZ1=i6GgH9Yja2cdmSueKD_As_g@mail.gmail.com
Reported-by: Jeffy Chen 
Reported-by: Brian Norris 
Signed-off-by: Alexandre Belloni