linux.git/drivers/clocksource, branch v6.18.8

riscv: clocksource: Fix stimecmp update hazard on RV32

2026-01-30T09:32:16+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/nxp-stm: Prevent driver unbind

2025-12-18T13:03:20+00:00

[ Upstream commit 6a2416892e8942f5e2bfe9b85c0164f410a53a2d ]

Clockevents cannot be deregistered so suppress the bind attributes to
prevent the driver from being unbound and releasing the underlying
resources after registration.

Even if the driver can currently only be built-in, also switch to
builtin_platform_driver() to prevent it from being unloaded should
modular builds ever be enabled.

Fixes: cec32ac75827 ("clocksource/drivers/nxp-timer: Add the System Timer Module for the s32gx platforms")
Signed-off-by: Johan Hovold 
Signed-off-by: Daniel Lezcano 
Link: https://patch.msgid.link/20251111153226.579-4-johan@kernel.org
Signed-off-by: Sasha Levin

clocksource/drivers/nxp-stm: Fix section mismatches

2025-12-18T13:03:20+00:00

[ Upstream commit b452d2c97eeccbf9c7ac5b3d2d9e80bf6d8a23db ]

Platform drivers can be probed after their init sections have been
discarded (e.g. on probe deferral or manual rebind through sysfs) so the
probe function must not live in init. Device managed resource actions
similarly cannot be discarded.

The "_probe" suffix of the driver structure name prevents modpost from
warning about this so replace it to catch any similar future issues.

Fixes: cec32ac75827 ("clocksource/drivers/nxp-timer: Add the System Timer Module for the s32gx platforms")
Signed-off-by: Johan Hovold 
Signed-off-by: Daniel Lezcano 
Cc: stable@vger.kernel.org	# 6.16
Cc: Daniel Lezcano 
Link: https://patch.msgid.link/20251017054943.7195-1-johan@kernel.org
Stable-dep-of: 6a2416892e89 ("clocksource/drivers/nxp-stm: Prevent driver unbind")
Signed-off-by: Sasha Levin

clocksource/drivers/nxp-pit: Prevent driver unbind

2025-12-18T13:03:20+00:00

[ Upstream commit e25f964cf414dafa6bee5c9c2c0b1d1fb041dc92 ]

The driver does not support unbinding (e.g. as clockevents cannot be
deregistered) so suppress the bind attributes to prevent the driver from
being unbound and rebound after registration (and disabling the timer
when reprobing fails).

Even if the driver can currently only be built-in, also switch to
builtin_platform_driver() to prevent it from being unloaded should
modular builds ever be enabled.

Fixes: bee33f22d7c3 ("clocksource/drivers/nxp-pit: Add NXP Automotive s32g2 / s32g3 support")
Signed-off-by: Johan Hovold 
Signed-off-by: Daniel Lezcano 
Link: https://patch.msgid.link/20251111153226.579-3-johan@kernel.org
Signed-off-by: Sasha Levin

clocksource/drivers/arm_arch_timer_mmio: Prevent driver unbind

2025-12-18T13:03:19+00:00

[ Upstream commit 6aa10f0e2ef9eba1955be6a9d0a8eaecf6bdb7ae ]

Clockevents cannot be deregistered so suppress the bind attributes to
prevent the driver from being unbound and releasing the underlying
resources after registration.

Fixes: 4891f01527bb ("clocksource/drivers/arm_arch_timer: Add standalone MMIO driver")
Signed-off-by: Johan Hovold 
Signed-off-by: Daniel Lezcano 
Acked-by: Marc Zyngier 
Link: https://patch.msgid.link/20251111153226.579-2-johan@kernel.org
Signed-off-by: Sasha Levin

clocksource/drivers/stm: Fix double deregistration on probe failure

2025-12-18T13:03:19+00:00

[ Upstream commit 6b38a8b31e2c5c2c3fd5f9848850788c190f216d ]

The purpose of the devm_add_action_or_reset() helper is to call the
action function in case adding an action ever fails so drop the clock
source deregistration from the error path to avoid deregistering twice.

Fixes: cec32ac75827 ("clocksource/drivers/nxp-timer: Add the System Timer Module for the s32gx platforms")
Signed-off-by: Johan Hovold 
Signed-off-by: Daniel Lezcano 
Cc: Daniel Lezcano 
Link: https://patch.msgid.link/20251017055039.7307-1-johan@kernel.org
Signed-off-by: Sasha Levin

clocksource/drivers/ralink: Fix resource leaks in init error path

2025-12-18T13:03:19+00:00

[ Upstream commit 2ba8e2aae1324704565a7d4d66f199d056c9e3c6 ]

The ralink_systick_init() function does not release all acquired resources
on its error paths. If irq_of_parse_and_map() or a subsequent call fails,
the previously created I/O memory mapping and IRQ mapping are leaked.

Add goto-based error handling labels to ensure that all allocated
resources are correctly freed.

Fixes: 1f2acc5a8a0a ("MIPS: ralink: Add support for systick timer found on newer ralink SoC")
Signed-off-by: Haotian Zhang 
Signed-off-by: Daniel Lezcano 
Link: https://patch.msgid.link/20251030090710.1603-1-vulab@iscas.ac.cn
Signed-off-by: Sasha Levin

Merge tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2025-10-07T15:40:15+00:00

Pull hyperv updates from Wei Liu:

 - Unify guest entry code for KVM and MSHV (Sean Christopherson)

 - Switch Hyper-V MSI domain to use msi_create_parent_irq_domain()
   (Nam Cao)

 - Add CONFIG_HYPERV_VMBUS and limit the semantics of CONFIG_HYPERV
   (Mukesh Rathor)

 - Add kexec/kdump support on Azure CVMs (Vitaly Kuznetsov)

 - Deprecate hyperv_fb in favor of Hyper-V DRM driver (Prasanna
   Kumar T S M)

 - Miscellaneous enhancements, fixes and cleanups (Abhishek Tiwari,
   Alok Tiwari, Nuno Das Neves, Wei Liu, Roman Kisel, Michael Kelley)

* tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hyperv: Remove the spurious null directive line
  MAINTAINERS: Mark hyperv_fb driver Obsolete
  fbdev/hyperv_fb: deprecate this in favor of Hyper-V DRM driver
  Drivers: hv: Make CONFIG_HYPERV bool
  Drivers: hv: Add CONFIG_HYPERV_VMBUS option
  Drivers: hv: vmbus: Fix typos in vmbus_drv.c
  Drivers: hv: vmbus: Fix sysfs output format for ring buffer index
  Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()
  x86/hyperv: Switch to msi_create_parent_irq_domain()
  mshv: Use common "entry virt" APIs to do work in root before running guest
  entry: Rename "kvm" entry code assets to "virt" to genericize APIs
  entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper
  mshv: Handle NEED_RESCHED_LAZY before transferring to guest
  x86/hyperv: Add kexec/kdump support on Azure CVMs
  Drivers: hv: Simplify data structures for VMBus channel close message
  Drivers: hv: util: Cosmetic changes for hv_utils_transport.c
  mshv: Add support for a new parent partition configuration
  clocksource: hyper-v: Skip unnecessary checks for the root partition
  hyperv: Add missing field to hv_output_map_device_interrupt

clocksource/drivers/sh_cmt: Split start/stop of clock source and events

2025-09-23T10:42:43+00:00

The CMT do a housekeeping such as dealing with runtime PM and
enable/disable clocks when either a clock source is enabled, or when a
new clock event is registered.

Doing this type of housekeeping for when a clock event is registered is
not always possible as it can happen in contexts where holding spinlocks
is not possible. However doing it when registering a clock source is
possible.

As a first step to address this design break apart the CMT start and
stop functions. The path for clock sources need not change, while the
one for clock events need to be reworked in future work.

There is no indented functional change, just breaking the two use-cases
controlled by a flag into two distinct functions.

Signed-off-by: Niklas Söderlund 
Signed-off-by: Daniel Lezcano 
Tested-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/20250910142657.1148696-2-niklas.soderlund+renesas@ragnatech.se

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

2025-09-23T10:42:27+00:00

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