kernel/linux.git/drivers/clocksource, branch v6.12.80

clocksource/drivers/timer-integrator-ap: Add missing Kconfig dependency on OF

2026-03-04T12:20:57+00:00

[ Upstream commit 2246464821e2820572e6feefca2029f17629cc50 ] This driver accesses the of_aliases global variable declared in linux/of.h and defined in drivers/base/of.c. It requires OF support or will cause a link failure. Add the missing Kconfig dependency. Closes: https://lore.kernel.org/oe-kbuild-all/202601152233.og6LdeUo-lkp@intel.com/ Signed-off-by: Bartosz Golaszewski Signed-off-by: Daniel Lezcano Link: https://patch.msgid.link/20260116111723.10585-1-bartosz.golaszewski@oss.qualcomm.com Signed-off-by: Sasha Levin

clocksource/drivers/sh_tmu: Always leave device running after probe

2026-03-04T12:20:57+00:00

[ Upstream commit b1278972b08e480990e2789bdc6a7c918bc349be ] The TMU device can be used as both a clocksource and a clockevent provider. The driver tries to be smart and power itself on and off, as well as enabling and disabling its clock when it's not in operation. This behavior is slightly altered if the TMU is used as an early platform device in which case the device is left powered on after probe, but the clock is still enabled and disabled at runtime. This has worked for a long time, but recent improvements in PREEMPT_RT and PROVE_LOCKING have highlighted an issue. As the TMU registers itself as a clockevent provider, clockevents_register_device(), it needs to use raw spinlocks internally as this is the context of which the clockevent framework interacts with the TMU driver. However in the context of holding a raw spinlock the TMU driver can't really manage its power state or clock with calls to pm_runtime_*() and clk_*() as these calls end up in other platform drivers using regular spinlocks to control power and clocks. This mix of spinlock contexts trips a lockdep warning. ============================= [ BUG: Invalid wait context ] 6.18.0-arm64-renesas-09926-gee959e7c5e34 #1 Not tainted ----------------------------- swapper/0/0 is trying to lock: ffff000008c9e180 (&dev->power.lock){-...}-{3:3}, at: __pm_runtime_resume+0x38/0x88 other info that might help us debug this: context-{5:5} 1 lock held by swapper/0/0: ccree e6601000.crypto: ARM CryptoCell 630P Driver: HW version 0xAF400001/0xDCC63000, Driver version 5.0 #0: ffff8000817ec298 ccree e6601000.crypto: ARM ccree device initialized (tick_broadcast_lock){-...}-{2:2}, at: __tick_broadcast_oneshot_control+0xa4/0x3a8 stack backtrace: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.18.0-arm64-renesas-09926-gee959e7c5e34 #1 PREEMPT Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT) Call trace: show_stack+0x14/0x1c (C) dump_stack_lvl+0x6c/0x90 dump_stack+0x14/0x1c __lock_acquire+0x904/0x1584 lock_acquire+0x220/0x34c _raw_spin_lock_irqsave+0x58/0x80 __pm_runtime_resume+0x38/0x88 sh_tmu_clock_event_set_oneshot+0x84/0xd4 clockevents_switch_state+0xfc/0x13c tick_broadcast_set_event+0x30/0xa4 __tick_broadcast_oneshot_control+0x1e0/0x3a8 tick_broadcast_oneshot_control+0x30/0x40 cpuidle_enter_state+0x40c/0x680 cpuidle_enter+0x30/0x40 do_idle+0x1f4/0x280 cpu_startup_entry+0x34/0x40 kernel_init+0x0/0x130 do_one_initcall+0x0/0x230 __primary_switched+0x88/0x90 For non-PREEMPT_RT builds this is not really an issue, but for PREEMPT_RT builds where normal spinlocks can sleep this might be an issue. Be cautious and always leave the power and clock running after probe. Signed-off-by: Niklas Söderlund Signed-off-by: Daniel Lezcano Tested-by: Geert Uytterhoeven Link: https://patch.msgid.link/20251202221341.1856773-1-niklas.soderlund+renesas@ragnatech.se Signed-off-by: Sasha Levin

riscv: clocksource: Fix stimecmp update hazard on RV32

2026-01-30T09:28:41+00:00

[ Upstream commit eaa9bb1d39d59e7c17b06cec12622b7c586ab629 ] On RV32, updating the 64-bit stimecmp (or vstimecmp) CSR requires two separate 32-bit writes. A race condition exists if the timer triggers during these two writes. The RISC-V Privileged Specification (e.g., Section 3.2.1 for mtimecmp) recommends a specific 3-step sequence to avoid spurious interrupts when updating 64-bit comparison registers on 32-bit systems: 1. Set the low-order bits (stimecmp) to all ones (ULONG_MAX). 2. Set the high-order bits (stimecmph) to the desired value. 3. Set the low-order bits (stimecmp) to the desired value. Current implementation writes the LSB first without ensuring a future value, which may lead to a transient state where the 64-bit comparison is incorrectly evaluated as "expired" by the hardware. This results in spurious timer interrupts. This patch adopts the spec-recommended 3-step sequence to ensure the intermediate 64-bit state is never smaller than the current time. Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available") Signed-off-by: Naohiko Shimizu Reviewed-by: Anup Patel Link: https://patch.msgid.link/20260104135938.524-2-naohiko.shimizu@gmail.com Signed-off-by: Paul Walmsley Signed-off-by: Sasha Levin

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