linux-stable.git/drivers/clocksource, branch v7.2.4

clocksource/drivers/timer-sun4i: Advertise a real minimum delta

2026-09-07T15:36:30+00:00

commit d21808328225ab8cee46885bf9a0dffcefbe630e upstream.

sun4i_clkevt_next_event() compensates for the timer stop/start
synchronization delay by programming evt - TIMER_SYNC_TICKS into the
hardware interval register. The clockevent device currently advertises
TIMER_SYNC_TICKS as min_delta_ticks, so the clockevents core is allowed
to call set_next_event() with evt == TIMER_SYNC_TICKS.

That programs a zero-tick interval. With oneshot/highres/nohz timer
operation this can leave the next event stuck, which was observed as a
boot hang on Allwinner D1 after the clockevents core started reusing
forced minimum-delta events.

Advertise one extra tick instead, so the smallest event accepted by the
core still programs at least one hardware tick after the synchronization
compensation.

Fixes: 12e1480bcb49 ("clocksource: sun4i: Report the minimum tick that we can program")
Reported-by: Indrek Kruusa 
Closes: https://lore.kernel.org/linux-riscv/CA+fTLhgLmTY+exGujKf8OYYQvcEW5X5NJ_5sLq2AYL6zER2c0A@mail.gmail.com/
Assisted-by: Codex:gpt-5.5
Signed-off-by: Felix Yan 
Signed-off-by: Daniel Lezcano 
Tested-by: Indrek Kruusa 
Acked-by: Jernej Skrabec 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-riscv/CA+fTLhgLmTY+exGujKf8OYYQvcEW5X5NJ_5sLq2AYL6zER2c0A@mail.gmail.com/
Link: https://patch.msgid.link/20260624220434.4183732-1-felixonmars@archlinux.org
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path

2026-09-07T15:36:30+00:00

commit 05520e035f8332c8e33f3011b5ca016fde61793d upstream.

When cpuhp_setup_state fails after pit_clockevent_per_cpu_init has
successfully called request_irq, the error handling jumps directly to
out_pit_clocksource_unregister without freeing the registered IRQ.

This leaks the IRQ line and, since kfree(pit) follows, leaves a
dangling pointer registered as the interrupt handler's dev_id,
potentially leading to a use-after-free if the IRQ fires afterwards.

Fix it by calling pit_clockevent_per_cpu_exit to properly release the
IRQ before falling through to the existing cleanup chain.

Suggested-by: Greg KH 
Fixes: bee33f22d7c3 ("clocksource/drivers/nxp-pit: Add NXP Automotive s32g2 / s32g3 support")
Cc: stable@vger.kernel.org
Signed-off-by: WenTao Liang 
Signed-off-by: Daniel Lezcano 
Link: https://patch.msgid.link/20260628130700.45680-1-vulab@iscas.ac.cn
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/arm_arch_timer: Workaround bcm2712 broken EL2 virtual timer

2026-08-12T15:09:29+00:00

It appears that the bcm2712 SoC found in the relatively popular RPi5 has a
broken EL2 virtual timer.

Tthe reason why the timer isn't working is unknown (the timer is ticking,
but the interrupt never fires), and the SoC vendor doesn't communicate on
the reason why this isn't working, leaving users and maintainers in the
dark.

Paper over the issue by detecting the broken HW, falling back to the
physical timer instead, and let the user know about it.  Also taint the
kernel as the machine is definitely not compliant with the spec, and it's
unknown what else is wrong with it.

Reported-by: John 
Reported-by: Daniel Drake 
Reported-by: Marek Szyprowski 
Signed-off-by: Marc Zyngier 
Signed-off-by: Thomas Gleixner 
Tested-by: Gary Guo 
Acked-by: Florian Fainelli 
Cc: Daniel Lezcano 
Link: https://patch.msgid.link/20260710080958.491620-1-maz@kernel.org

Merge tag 'timers-vdso-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

2026-06-15T08:27:13+00:00

Pull vdso updates from Thomas Gleixner:

 - Remove the redundant CONFIG_GENERIC_TIME_VSYSCALL after converting
   the remaining users over.

 - Rework and sanitize the MIPS VDSO handling, so it does not handle the
   time related VDSO if there is no VDSO capable clocksource available.
   Also stop mapping VDSO data pages unconditionally even if there is no
   usage possible.

* tag 'timers-vdso-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  MIPS: VDSO: Fold MIPS_CLOCK_VSYSCALL into MIPS_GENERIC_GETTIMEOFDAY
  MIPS: VDSO: Gate microMIPS restriction on GCC version
  MIPS: VDSO: Fold MIPS_DISABLE_VDSO into MIPS_GENERIC_GETTIMEOFDAY
  clocksource/drivers/mips-gic-timer: Only use VDSO_CLOCKMODE_GIC when it is a available
  MIPS: csrc-r4k: Only use VDSO_CLOCKMODE_R4K when it is a available
  MIPS: VDSO: Only map the data pages when the vDSO is used
  MIPS: Introduce Kconfig MIPS_GENERIC_GETTIMEOFDAY
  vdso/datastore: Always provide symbol declarations
  MAINTAINERS: Add include/linux/vdso_datastore.h to vDSO block
  vdso/gettimeofday: Rename __arch_get_vdso_u_timens_data()
  vdso/treewide: Drop GENERIC_TIME_VSYSCALL
  vdso/vsyscall: Gate update_vsyscall() behind CONFIG_GENERIC_GETTIMEOFDAY
  riscv: vdso: Drop CONFIG_GENERIC_TIME_VSYSCALL guard around syscall fallbacks

Merge tag 'timers-ptp-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

2026-06-15T08:21:27+00:00

Pull timekeeping updates from Thomas Gleixner:
 "Updates for NTP/timekeeping and PTP:

   - Expand timekeeping snapshot mechanisms

     The various snapshot functions are mostly used for PTP to collect
     "atomic" snapshots of various involved clocks.

     They lack support for the recently introduced AUX clocks and do not
     provide the underlying counter value (e.g. TSC) to user space.
     Exposing the counter value snapshot allows for better control and
     steering.

     Convert the hard wired ktime_get_snapshot() to take a clock ID,
     which allows the caller to select the clock ID to be captured along
     with CLOCK_MONONOTONIC_RAW. Additionally capture the underlying
     hardware counter value and the clock source ID of the counter.

     Expand the hardware based snapshot capture where devices provide a
     mechanism to snapshot the hardware PTP clock and the system counter
     (usually via PCI/PTM) to support AUX clocks and also provide the
     captured counter value back to the caller and not only the clock
     timestamps derived from it.

   - Add a new optional read_snapshot() callback to clocksources

     That is required to capture atomic snapshots from clocksources
     which are derived from TSC with a scaling mechanism (e.g. Hyper-V,
     KVMclock).

     The value pair is handed back in the snapshot structure to the
     callers, so they can do the necessary correlations in a more
     precise way.

  This touches usage sites of the affected functions and data structure
  all over the tree, but stays fully backwards compatible for the
  existing user space exposed interfaces. New PTP IOCTLs will provide
  access to the extended functionality in later kernel versions"

* tag 'timers-ptp-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (28 commits)
  ptp: vmclock: Use hw_cycles from snapshot for precise TSC pairing
  x86/kvmclock: Implement read_snapshot() for kvmclock clocksource
  clocksource/hyperv: Implement read_snapshot() for TSC page clocksource
  timekeeping: Add clocksource read_snapshot() method and hw_cycles to snapshot
  ptp: Switch to ktime_get_snapshot_id() for pre/post timestamps
  timekeeping: Add support for AUX clock cross timestamping
  timekeeping: Remove system_device_crosststamp::sys_realtime
  ALSA: hda/common: Use system_device_crosststamp::sys_systime
  wifi: iwlwifi: Use system_device_crosststamp::sys_systime
  ptp: Use system_device_crosststamp::sys_systime
  timekeeping: Prepare for cross timestamps on arbitrary clock IDs
  timekeeping: Remove ktime_get_snapshot()
  virtio_rtc: Use provided clock ID for history snapshot
  net/mlx5: Use provided clock ID for history snapshot
  igc: Use provided clock ID for history snapshot
  ice/ptp: Use provided clock ID for history snapshot
  wifi: iwlwifi: Adopt PTP cross timestamps to core changes
  timekeeping: Add CLOCK ID to system_device_crosststamp
  timekeeping: Add system_counterval_t to struct system_device_crosststamp
  timekeeping: Add CLOCK_AUX support for ktime_get_snapshot_id()
  ...

clocksource: move NXP timer selection to drivers/clocksource

2026-06-10T05:26:07+00:00

The Kconfig logic for selecting the scheduler clocksource on
NXP Vybrid (VF610) uses a `choice` block restricted to 32-bit ARM. This
prevents 64-bit architectures, such as the NXP S32 family, from enabling
the NXP Periodic Interrupt Timer (PIT) driver (CONFIG_NXP_PIT_TIMER).

Relocate the NXP clocksource selection from arch/arm/mach-imx/Kconfig to
drivers/clocksource/Kconfig. This allows the configuration to be shared
across different architectures.

Update the selection to include support for ARCH_S32 and add a "None"
option restricted to ARCH_S32, since Vybrid lacks the ARM Architected
Timer. The Vybrid Global Timer option is restricted to ARCH_MULTI_V7
SOC_VF610 platforms to prevent it from being visible on Cortex-M4 builds,
which lack the ARM Global Timer hardware.

Fixes: bee33f22d7c3 ("clocksource/drivers/nxp-pit: Add NXP Automotive s32g2 / s32g3 support")
Signed-off-by: Enric Balletbo i Serra 
Signed-off-by: Daniel Lezcano 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260514-fix-nxp-timer-v3-1-a3e68fdb505e@redhat.com

clocksource/drivers/timer-tegra186: Reserve and service a kernel watchdog

2026-06-10T05:25:54+00:00

Tegra SoCs supports multiple watchdog timers. If the kernel crashes or
hangs before userspace enables a watchdog, the system cannot recover and
may remain bricked, e.g. after a failed OTA update. The driver currently
leaves all watchdogs disabled until userspace configures them.

Reserve first available watchdog as a kernel-only watchdog for Tegra186
and Tegra234. Arm it during probe (120s timeout) and keep it alive in
the driver IRQ handler. Do not register it to userspace. Other available
watchdogs remain exposed to userspace. This guarantees the system can
reset itself in case of a hang or crash even when userspace never starts.

Signed-off-by: Kartik Rajput 
Signed-off-by: Daniel Lezcano 
Reviewed-by: Jon Hunter 
Link: https://patch.msgid.link/20260507154557.2082697-5-kkartik@nvidia.com

clocksource/drivers/timer-tegra186: Register all accessible watchdog timers

2026-06-10T05:25:40+00:00

Tegra186+ SoCs expose multiple watchdog timers, but the driver only
registers WDT(0).

Iterate over num_wdts and, for each WDT, check the SCR (firewall) registers
in the TKE block to determine whether Linux has read and write access.
Register the watchdogs that are accessible.

Signed-off-by: Kartik Rajput 
Signed-off-by: Daniel Lezcano 
Reviewed-by: Jon Hunter 
Link: https://patch.msgid.link/20260507154557.2082697-4-kkartik@nvidia.com

clocksource/drivers/timer-tegra186: Correct num_wdts for Tegra186 and Tegra234

2026-06-10T05:25:26+00:00

On Tegra186 and Tegra234, WDT2 is connected to the Audio Processing
Engine (APE) and cannot be accessed from Linux. Only WDT0 and WDT1
are accessible to Linux.

Update num_wdts from 3 to 2 for both Tegra186 and Tegra234 to reflect
the actual number of watchdogs available to Linux.

Signed-off-by: Kartik Rajput 
Signed-off-by: Daniel Lezcano 
Reviewed-by: Jon Hunter 
Link: https://patch.msgid.link/20260507154557.2082697-3-kkartik@nvidia.com

clocksource/drivers/timer-tegra186: Fix support for multiple watchdog instances

2026-06-10T05:25:08+00:00

Tegra SoCs support multiple watchdogs; currently only one (WDT0) is
used. When multiple watchdogs are registered, tegra186_wdt_enable()
overwrites the TKEIE(x) register, discarding any existing watchdog
interrupt enable bits. As a result, enabling one watchdog inadvertently
disables interrupts for the others.

Fix this by preserving the existing TKEIE(x) value and updating it
using a read-modify-write sequence.

Fixes: 42cee19a9f83 ("clocksource: Add Tegra186 timers support")
Cc: stable@vger.kernel.org
Signed-off-by: Kartik Rajput 
Signed-off-by: Daniel Lezcano 
Reviewed-by: Jon Hunter 
Link: https://patch.msgid.link/20260507154557.2082697-2-kkartik@nvidia.com