All the idle routines are called with RCU disabled, as such there must not be any tracing inside. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> --- drivers/acpi/processor_idle.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -108,8 +108,8 @@ static const struct dmi_system_id proces static void __cpuidle acpi_safe_halt(void) { if (!tif_need_resched()) { - safe_halt(); - local_irq_disable(); + raw_safe_halt(); + raw_local_irq_disable(); } } @@ -524,16 +524,21 @@ static int acpi_idle_bm_check(void) return bm_status; } -static void wait_for_freeze(void) +static __cpuidle void io_idle(unsigned long addr) { + /* IO port based C-state */ + inb(addr); + #ifdef CONFIG_X86 /* No delay is needed if we are in guest */ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) return; #endif - /* Dummy wait op - must do something useless after P_LVL2 read - because chipsets cannot guarantee that STPCLK# signal - gets asserted in time to freeze execution properly. */ + /* + * Dummy wait op - must do something useless after P_LVL2 read + * because chipsets cannot guarantee that STPCLK# signal + * gets asserted in time to freeze execution properly. + */ inl(acpi_gbl_FADT.xpm_timer_block.address); } @@ -553,9 +558,7 @@ static void __cpuidle acpi_idle_do_entry } else if (cx->entry_method == ACPI_CSTATE_HALT) { acpi_safe_halt(); } else { - /* IO port based C-state */ - inb(cx->address); - wait_for_freeze(); + io_idle(cx->address); } perf_lopwr_cb(false); @@ -577,8 +580,7 @@ static int acpi_idle_play_dead(struct cp if (cx->entry_method == ACPI_CSTATE_HALT) safe_halt(); else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { - inb(cx->address); - wait_for_freeze(); + io_idle(cx->address); } else return -ENODEV;