On 05/09/2025 18:24, Mostafa Saleh wrote: > Booting the kernel on Pixel-6 with `CONFIG_DEBUG_PREEMPT` prints the > following WARN: > > [ 0.784187][ T1] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 > [ 0.784328][ T1] caller is debug_smp_processor_id+0x20/0x30 > [ 0.784433][ T1] CPU: 6 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-rc4-gd69eb204c255 #1 PREEMPT > [ 0.784439][ T1] Hardware name: Oriole (DT) > [ 0.784441][ T1] Call trace: > [ 0.784443][ T1] show_stack+0x34/0xa0 (C) > [ 0.784453][ T1] dump_stack_lvl+0x7c/0xb0 > [ 0.784460][ T1] dump_stack+0x18/0x24 > [ 0.784464][ T1] check_preemption_disabled+0xf8/0x100 > [ 0.784470][ T1] debug_smp_processor_id+0x20/0x30 > [ 0.784476][ T1] gs101_cpuhp_pmu_online+0x40/0x108 > [ 0.784483][ T1] cpuhp_invoke_callback+0x188/0x2d8 > [ 0.784490][ T1] cpuhp_issue_call+0xec/0x240 > [ 0.784494][ T1] __cpuhp_setup_state_cpuslocked+0x140/0x2c0 > [ 0.784499][ T1] __cpuhp_setup_state+0x58/0x88 > [ 0.784504][ T1] exynos_pmu_probe+0x2a4/0x380 > [ 0.784508][ T1] platform_probe+0x64/0xd0 > [ 0.784516][ T1] really_probe+0xd0/0x3b0 > [ 0.784520][ T1] __driver_probe_device+0x8c/0x170 > [ 0.784524][ T1] driver_probe_device+0x44/0x140 > [ 0.784528][ T1] __device_attach_driver+0xd8/0x180 > [ 0.784532][ T1] bus_for_each_drv+0x90/0xf8 > [ 0.784536][ T1] __device_attach+0xa8/0x1d0 > [ 0.784540][ T1] device_initial_probe+0x1c/0x30 > [ 0.784544][ T1] bus_probe_device+0xb4/0xc0 > [ 0.784547][ T1] device_add+0x4d0/0x700 > [ 0.784550][ T1] of_device_add+0x4c/0x78 > [ 0.784556][ T1] of_platform_device_create_pdata+0x9c/0x148 > [ 0.784560][ T1] of_platform_bus_create+0x1d0/0x370 > [ 0.784563][ T1] of_platform_bus_create+0x234/0x370 > [ 0.784567][ T1] of_platform_populate+0x84/0x178 > [ 0.784571][ T1] of_platform_default_populate_init+0xf0/0x120 > [ 0.784579][ T1] do_one_initcall+0x68/0x2d0 > [ 0.784585][ T1] kernel_init_freeable+0x2d8/0x358 > [ 0.784589][ T1] kernel_init+0x28/0x168 > [ 0.784595][ T1] ret_from_fork+0x10/0x20 Please trim from unnecessary parts - [time]. > > As this value is only read once, it doesn't require to be stable, so Why it does not need to be stable? Onlining wrong CPU number is not desired... > just use "raw_smp_processor_id" instead. You might be just hiding some other real issue, because above stacktrace is from gs101_cpuhp_pmu_online() which IRQs disabled and preemption disabled. Provide analysis of the warning, instead of just making it disappear. > > Cc: Peter Griffin <peter.griffin@xxxxxxxxxx> > Cc: André Draszik <andre.draszik@xxxxxxxxxx> > No blank lines between tags. Missing Fixes tag... and then Cc is not necessary. Please follow standard kernel process. > Signed-off-by: Mostafa Saleh <smostafa@xxxxxxxxxx> > --- > drivers/soc/samsung/exynos-pmu.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c > index a77288f49d24..338f4758a089 100644 > --- a/drivers/soc/samsung/exynos-pmu.c > +++ b/drivers/soc/samsung/exynos-pmu.c > @@ -338,7 +338,7 @@ EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap_by_phandle); > Best regards, Krzysztof
