On 2022-12-19 16:15:00 [+0100], Krzysztof Kozlowski wrote: > The PSCI cpuidle power domain in power_off callback uses > __this_cpu_write() so it is PREEMPT_RT safe. This allows to use it in Why does __this_cpu_write() matter here? > Realtime kernels and solves errors like: > > BUG: scheduling while atomic: swapper/2/0/0x00000002 > Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) > Call trace: > dump_backtrace.part.0+0xe0/0xf0 > show_stack+0x18/0x40 > dump_stack_lvl+0x68/0x84 > dump_stack+0x18/0x34 > __schedule_bug+0x60/0x80 > __schedule+0x628/0x800 > schedule_rtlock+0x28/0x5c > rtlock_slowlock_locked+0x360/0xd30 > rt_spin_lock+0x88/0xb0 > genpd_lock_nested_spin+0x1c/0x30 > genpd_power_off.part.0.isra.0+0x20c/0x2a0 > genpd_runtime_suspend+0x150/0x2bc > __rpm_callback+0x48/0x170 > rpm_callback+0x6c/0x7c > rpm_suspend+0x108/0x660 > __pm_runtime_suspend+0x4c/0x8c > __psci_enter_domain_idle_state.constprop.0+0x54/0xe0 > psci_enter_domain_idle_state+0x18/0x2c > cpuidle_enter_state+0x8c/0x4e0 > cpuidle_enter+0x38/0x50 > do_idle+0x248/0x2f0 > cpu_startup_entry+0x24/0x30 > secondary_start_kernel+0x130/0x154 > __secondary_switched+0xb0/0xb4 This is to a sleeping lock (spinlock_t) in an IRQ-off region which starts in do_idle(). You could describe the problem and to solution you aim for instead pasting a backtrace into the commit description and adding a flow in the code. I don't see how your commit description matches your change in code. One might think "Oh. If I see this pattern, I need an irqsafe lock to fix it". Sebastian
