linux.git/drivers/clocksource, branch v6.12.62

clocksource/drivers/timer-rtl-otto: Do not interfere with interrupts

2025-11-13T20:34:07+00:00

[ Upstream commit c445bffbf28f721e05d0ce06895045fc62aaff7c ]

During normal operation the timers are reprogrammed including an
interrupt acknowledgement. This has no effect as the whole timer
is setup from scratch afterwards. Especially in an interrupt this
has already been done by rttm_timer_interrupt().

Change the behaviour as follows:

- Use rttm_disable_timer() during reprogramming
- Keep rttm_stop_timer() for all other use cases.

Downstream has already tested and confirmed a patch. See
https://github.com/openwrt/openwrt/pull/19468
https://forum.openwrt.org/t/support-for-rtl838x-based-managed-switches/57875/3788

Signed-off-by: Markus Stockhausen 
Signed-off-by: Daniel Lezcano 
Tested-by: Stephen Howell 
Tested-by: Bjørn Mork 
Link: https://lore.kernel.org/r/20250804080328.2609287-4-markus.stockhausen@gmx.de
Signed-off-by: Sasha Levin

clocksource/drivers/timer-rtl-otto: Work around dying timers

2025-11-13T20:34:07+00:00

[ Upstream commit e7a25106335041aeca4fdf50a84804c90142c886 ]

The OpenWrt distribution has switched from kernel longterm 6.6 to
6.12. Reports show that devices with the Realtek Otto switch platform
die during operation and are rebooted by the watchdog. Sorting out
other possible reasons the Otto timer is to blame. The platform
currently consists of 4 targets with different hardware revisions.
It is not 100% clear which devices and revisions are affected.

Analysis shows:

A more aggressive sched/deadline handling leads to more timer starts
with small intervals. This increases the bug chances. See
https://marc.info/?l=linux-kernel&m=175276556023276&w=2

Focusing on the real issue a hardware limitation on some devices was
found. There is a minimal chance that a timer ends without firing an
interrupt if it is reprogrammed within the 5us before its expiration
time. Work around this issue by introducing a bounce() function. It
restarts the timer directly before the normal restart functions as
follows:

- Stop timer
- Restart timer with a slow frequency.
- Target time will be >5us
- The subsequent normal restart is outside the critical window

Downstream has already tested and confirmed a patch. See
https://github.com/openwrt/openwrt/pull/19468
https://forum.openwrt.org/t/support-for-rtl838x-based-managed-switches/57875/3788

Signed-off-by: Markus Stockhausen 
Signed-off-by: Daniel Lezcano 
Tested-by: Stephen Howell 
Tested-by: Bjørn Mork 
Link: https://lore.kernel.org/r/20250804080328.2609287-2-markus.stockhausen@gmx.de
Signed-off-by: Sasha Levin

clocksource/drivers/vf-pit: Replace raw_readl/writel to readl/writel

2025-11-13T20:34:07+00:00

[ Upstream commit 0b781f527d6f99e68e5b3780ae03cd69a7cb5c0c ]

The driver uses the raw_readl() and raw_writel() functions. Those are
not for MMIO devices. Replace them with readl() and writel()

[ dlezcano: Fixed typo in the subject s/reald/readl/ ]

Signed-off-by: Daniel Lezcano 
Acked-by: Arnd Bergmann 
Cc: Arnd Bergmann 
Link: https://lore.kernel.org/r/20250804152344.1109310-2-daniel.lezcano@linaro.org
Signed-off-by: Sasha Levin

clocksource/drivers/clps711x: Fix resource leaks in error paths

2025-10-19T14:33:34+00:00

commit cd32e596f02fc981674573402c1138f616df1728 upstream.

The current implementation of clps711x_timer_init() has multiple error
paths that directly return without releasing the base I/O memory mapped
via of_iomap(). Fix of_iomap leaks in error paths.

Fixes: 04410efbb6bc ("clocksource/drivers/clps711x: Convert init function to return error")
Fixes: 2a6a8e2d9004 ("clocksource/drivers/clps711x: Remove board support")
Signed-off-by: Zhen Ni 
Signed-off-by: Daniel Lezcano 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250814123324.1516495-1-zhen.ni@easystack.cn
Signed-off-by: Greg Kroah-Hartman

clocksource: mips-gic-timer: Enable counter when CPUs start

2025-05-29T09:02:41+00:00

[ Upstream commit 3128b0a2e0cf6e07aa78e5f8cf7dd9cd59dc8174 ]

In multi-cluster MIPS I6500 systems there is a GIC in each cluster,
each with its own counter. When a cluster powers up the counter will
be stopped, with the COUNTSTOP bit set in the GIC_CONFIG register.

In single cluster systems, it has been fine to clear COUNTSTOP once
in gic_clocksource_of_init() to start the counter. In multi-cluster
systems, this will only have started the counter in the boot cluster,
and any CPUs in other clusters will find their counter stopped which
will break the GIC clock_event_device.

Resolve this by having CPUs clear the COUNTSTOP bit when they come
online, using the existing gic_starting_cpu() CPU hotplug callback. This
will allow CPUs in secondary clusters to ensure that the cluster's GIC
counter is running as expected.

Signed-off-by: Paul Burton 
Signed-off-by: Chao-ying Fu 
Signed-off-by: Dragan Mladjenovic 
Signed-off-by: Aleksandar Rikalo 
Reviewed-by: Philippe Mathieu-Daudé 
Tested-by: Serge Semin 
Tested-by: Gregory CLEMENT 
Acked-by: Daniel Lezcano 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

clocksource/drivers/timer-riscv: Stop stimecmp when cpu hotplug

2025-05-29T09:02:14+00:00

[ Upstream commit 70c93b026ed07078e933583591aa9ca6701cd9da ]

Stop the timer when the cpu is going to be offline otherwise the
timer interrupt may be pending while performing power-down.

Suggested-by: Anup Patel 
Link: https://lore.kernel.org/lkml/20240829033904.477200-3-nick.hu@sifive.com/T/#u
Signed-off-by: Nick Hu 
Reviewed-by: Anup Patel 
Acked-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20250219114135.27764-3-nick.hu@sifive.com
Signed-off-by: Alexandre Ghiti 
Signed-off-by: Sasha Levin

clocksource/i8253: Use raw_spinlock_irqsave() in clockevent_i8253_disable()

2025-05-18T06:24:54+00:00

commit 94cff94634e506a4a44684bee1875d2dbf782722 upstream.

On x86 during boot, clockevent_i8253_disable() can be invoked via
x86_late_time_init -> hpet_time_init() -> pit_timer_init() which happens
with enabled interrupts.

If some of the old i8253 hardware is actually used then lockdep will notice
that i8253_lock is used in hard interrupt context. This causes lockdep to
complain because it observed the lock being acquired with interrupts
enabled and in hard interrupt context.

Make clockevent_i8253_disable() acquire the lock with
raw_spinlock_irqsave() to cure this.

[ tglx: Massage change log and use guard() ]

Fixes: c8c4076723dac ("x86/timer: Skip PIT initialization on modern chipsets")
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250404133116.p-XRWJXf@linutronix.de
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/stm32-lptimer: Use wakeup capable instead of init wakeup

2025-04-20T08:15:39+00:00

commit 96bf4b89a6ab22426ad83ef76e66c72a5a8daca0 upstream.

"wakeup-source" property describes a device which has wakeup capability
but should not force this device as a wakeup source.

Fixes: 48b41c5e2de6 ("clocksource: Add Low Power STM32 timers driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Torgue 
Signed-off-by: Fabrice Gasnier 
Rule: add
Link: https://lore.kernel.org/stable/20250306083407.2374894-1-fabrice.gasnier%40foss.st.com
Link: https://lore.kernel.org/r/20250306102501.2980153-1-fabrice.gasnier@foss.st.com
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

irqchip/jcore-aic, clocksource/drivers/jcore: Fix jcore-pit interrupt request

2025-02-27T12:30:21+00:00

[ Upstream commit d7e3fd658248f257006227285095d190e70ee73a ]

The jcore-aic irqchip does not have separate interrupt numbers reserved for
cpu-local vs global interrupts. Therefore the device drivers need to
request the given interrupt as per CPU interrupt.

69a9dcbd2d65 ("clocksource/drivers/jcore: Use request_percpu_irq()")
converted the clocksource driver over to request_percpu_irq(), but failed
to do add all the required changes, resulting in a failure to register PIT
interrupts.

Fix this by:

 1) Explicitly mark the interrupt via irq_set_percpu_devid() in
    jcore_pit_init().

 2) Enable and disable the per CPU interrupt in the CPU hotplug callbacks.

 3) Pass the correct per-cpu cookie to the irq handler by using
    handle_percpu_devid_irq() instead of handle_percpu_irq() in
    handle_jcore_irq().

[ tglx: Massage change log ]

Fixes: 69a9dcbd2d65 ("clocksource/drivers/jcore: Use request_percpu_irq()")
Signed-off-by: Artur Rojek 
Signed-off-by: Thomas Gleixner 
Acked-by: Uros Bizjak 
Link: https://lore.kernel.org/all/20250216175545.35079-3-contact@artur-rojek.eu
Signed-off-by: Sasha Levin

x86/hyperv: Fix hv tsc page based sched_clock for hibernation

2024-12-27T13:02:15+00:00

commit bcc80dec91ee745b3d66f3e48f0ec2efdea97149 upstream.

read_hv_sched_clock_tsc() assumes that the Hyper-V clock counter is
bigger than the variable hv_sched_clock_offset, which is cached during
early boot, but depending on the timing this assumption may be false
when a hibernated VM starts again (the clock counter starts from 0
again) and is resuming back (Note: hv_init_tsc_clocksource() is not
called during hibernation/resume); consequently,
read_hv_sched_clock_tsc() may return a negative integer (which is
interpreted as a huge positive integer since the return type is u64)
and new kernel messages are prefixed with huge timestamps before
read_hv_sched_clock_tsc() grows big enough (which typically takes
several seconds).

Fix the issue by saving the Hyper-V clock counter just before the
suspend, and using it to correct the hv_sched_clock_offset in
resume. This makes hv tsc page based sched_clock continuous and ensures
that post resume, it starts from where it left off during suspend.
Override x86_platform.save_sched_clock_state and
x86_platform.restore_sched_clock_state routines to correct this as soon
as possible.

Note: if Invariant TSC is available, the issue doesn't happen because
1) we don't register read_hv_sched_clock_tsc() for sched clock:
See commit e5313f1c5404 ("clocksource/drivers/hyper-v: Rework
clocksource and sched clock setup");
2) the common x86 code adjusts TSC similarly: see
__restore_processor_state() ->  tsc_verify_tsc_adjust(true) and
x86_platform.restore_sched_clock_state().

Cc: stable@vger.kernel.org
Fixes: 1349401ff1aa ("clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation")
Co-developed-by: Dexuan Cui 
Signed-off-by: Dexuan Cui 
Signed-off-by: Naman Jain 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20240917053917.76787-1-namjain@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20240917053917.76787-1-namjain@linux.microsoft.com>
Signed-off-by: Greg Kroah-Hartman