From 7ca380f60626d90cdd17cc60de5e756422e35b2a Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Fri, 20 Dec 2013 19:47:26 +0100 Subject: [PATCH] ACPI / cpuidle: fix max idle state handling with hotplug CPU support acpi_processor_hotplug() calls acpi_processor_setup_cpuidle_cx() without calling acpi_processor_setup_cpuidle_states() first so it is possible that dev->state_count becomes different from drv->state_count (in case of SMP system with unsupported C2/C3 states + enabled CPU hotplug and num_online_cpus() becoming > 1). The driver code assumes that cpuidle core will handle such cases but currently this is untrue (dev->state_count is used only for handling cpuidle state sysfs entries and drv->state_count is used for all other cases) and will not be fixed in the future as dev->state_count is planned to be removed. Fix the issue by checking for the max supported idle state in C2/C3 state's ->enter handler (acpi_idle_enter_simple() for C2/C3 and acpi_idle_enter_bm() for C3 + bm_check flag set) and setting the C1 state (instead of higher states) when needed. Also remove no longer needed max idle state checks from acpi_processor_setup_cpuidle_[states,cx](). Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Cc: Len Brown Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 644516d9bde6..45e3b81d6c29 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -785,6 +785,13 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, if (unlikely(!pr)) return -EINVAL; +#ifdef CONFIG_HOTPLUG_CPU + if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && + !pr->flags.has_cst && + !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) + return acpi_idle_enter_c1(dev, drv, CPUIDLE_DRIVER_STATE_START); +#endif + if (cx->entry_method == ACPI_CSTATE_FFH) { if (current_set_polling_and_test()) return -EINVAL; @@ -831,6 +838,13 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, if (unlikely(!pr)) return -EINVAL; +#ifdef CONFIG_HOTPLUG_CPU + if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && + !pr->flags.has_cst && + !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) + return acpi_idle_enter_c1(dev, drv, CPUIDLE_DRIVER_STATE_START); +#endif + if (!cx->bm_sts_skip && acpi_idle_bm_check()) { if (drv->safe_state_index >= 0) { return drv->states[drv->safe_state_index].enter(dev, @@ -932,12 +946,6 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, if (!cx->valid) continue; -#ifdef CONFIG_HOTPLUG_CPU - if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && - !pr->flags.has_cst && - !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) - continue; -#endif per_cpu(acpi_cstate[count], dev->cpu) = cx; count++; @@ -987,13 +995,6 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) if (!cx->valid) continue; -#ifdef CONFIG_HOTPLUG_CPU - if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && - !pr->flags.has_cst && - !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) - continue; -#endif - state = &drv->states[count]; snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); -- 2.20.1