Known issue: next-20250513: Juno-r2: WARNING kernel time clockevents.c cev_delta2ns clockevents_config.part

Regression while booting Juno-r2 with the Linux next-20250606 the following kernel warnings found.

This boot warning was reproduced with juno-r2.dtb and juno-r2-scmi.dtb.

Regressions found on Juno-r2 - boot warning

Regression Analysis: - New regression? Yes - Reproducibility? Yes

First seen on the next-20250606 Good: next-20250512 Bad: next-20250606

The suspected patch that found between tags is,

arch/arm64/boot/dts/arm/juno-base.dtsi commit 1fa3ed04ac55134063e3cd465b41aeb26715e52a Author: Sudeep Holla sudeep.holla@arm.com Date: Mon May 12 11:11:32 2025 +0100

arm64: dts: arm: Drop the clock-frequency property from timer nodes

Drop the clock-frequency property from the timer nodes, since it must be
configured by the boot/secure firmware.

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Message-Id: <20250512101132.1743920-1-sudeep.holla@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi index 055764d0b9e5..9ccb80821bdb 100644 --- a/arch/arm64/boot/dts/arm/juno-base.dtsi +++ b/arch/arm64/boot/dts/arm/juno-base.dtsi @@ -10,7 +10,6 @@ / { memtimer: timer@2a810000 { compatible = "arm,armv7-timer-mem"; reg = <0x0 0x2a810000 0x0 0x10000>; - clock-frequency = <50000000>; #address-cells = <1>; #size-cells = <1>; ranges = <0 0x0 0x2a820000 0x20000>;

Boot regression: Juno-r2 WARNING kernel time clockevents.c cev_delta2ns clockevents_config.part

Reported-by: Linux Kernel Functional Testing lkft@linaro.org

[ 0.000000] timer_sp804: timer clock not found: -517 [ 0.000000] timer_sp804: arm,sp804 clock not found: -2 [ 0.000000] Failed to initialize '/bus@8000000/motherboard-bus@8000000/iofpga-bus@300000000/timer@110000': -22 [ 0.000000] timer_sp804: timer clock not found: -517 [ 0.000000] timer_sp804: arm,sp804 clock not found: -2 [ 0.000000] Failed to initialize '/bus@8000000/motherboard-bus@8000000/iofpga-bus@300000000/timer@120000': -22 [ 0.000000] arch_timer: frequency not available [ 0.000000] ------------[ cut here ]------------ [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/time/clockevents.c:38 cev_delta2ns (kernel/time/clockevents.c:38 (discriminator 1)) [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-next-20250605 #1 PREEMPT [ 0.000000] Hardware name: ARM Juno development board (r2) (DT) [ 0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.000000] pc : cev_delta2ns (kernel/time/clockevents.c:38 (discriminator 1)) [ 0.000000] lr : clockevents_config.part.0 (kernel/time/clockevents.c:499) [ 0.000000] sp : ffff800082923cd0 [ 0.000000] x29: ffff800082923cd0 x28: 0000000000000400 x27: ffff800081650000 [ 0.000000] x26: ffff80008292fcc0 x25: ffff800082425888 x24: ffff8000829343c0 [ 0.000000] x23: ffff800083210000 x22: 000000000000000b x21: ffff8000823cf178 [ 0.000000] x20: ffff800082433880 x19: ffff00080021e240 x18: 0000000000000000 [ 0.000000] x17: ffff00080021a400 x16: ffff00080021a200 x15: 0000000000000100 [ 0.000000] x14: fffffdffe0008a00 x13: ffff800080000000 x12: 0000000000000000 [ 0.000000] x11: 0000000000000068 x10: 0000000000000100 x9 : ffff8000801b50f8 [ 0.000000] x8 : 000000001dcd6500 x7 : 000000003b9aca00 x6 : 0000000000000020 [ 0.000000] x5 : 0000000000000020 x4 : 0000000000000000 x3 : 0000000f00000000 [ 0.000000] x2 : 0000000000000000 x1 : ffff00080021e240 x0 : 000000000000000f [ 0.000000] Call trace: [ 0.000000] cev_delta2ns (kernel/time/clockevents.c:38 (discriminator 1)) (P) [ 0.000000] clockevents_config_and_register (kernel/time/clockevents.c:519) [ 0.000000] arch_timer_mem_frame_register (drivers/clocksource/arm_arch_timer.c:1319 drivers/clocksource/arm_arch_timer.c:1580) [ 0.000000] arch_timer_mem_of_init (drivers/clocksource/arm_arch_timer.c:1653) [ 0.000000] timer_probe (drivers/clocksource/timer-probe.c:31) [ 0.000000] time_init (arch/arm64/kernel/time.c:62) [ 0.000000] start_kernel (init/main.c:1014) [ 0.000000] __primary_switched (arch/arm64/kernel/head.S:247) [ 0.000000] ---[ end trace 0000000000000000 ]--- [ 0.000000] arch_timer: cp15 and mmio timer(s) running at 50.00MHz (phys/phys).

• Kernel version: 6.15.0-next-20250513 to 6.15.0-next-20250606
• Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
• Git sha: 4f27f06ec12190c7c62c722e99ab6243dea81a94
• Toolchain: gcc-13

• Boot lava log: https://lkft.validation.linaro.org/scheduler/job/8309469#L622
• Boot log: https://qa-reports.linaro.org/api/testruns/28679128/log_file/
• Boot warning: https://regressions.linaro.org/lkft/linux-next-master/next-20250605/log-parser-boot/exception-warning-cpu-pid-at-kerneltimeclockevents-cev_delta2ns/
• Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/2y4wgEvmeoVH3Vr528M4YN2OBXY/
• Kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/2y4wgEvmeoVH3Vr528M4YN2OBXY/config