ACPI / cpuidle: fix max idle state handling with hotplug CPU support (7ca380f6) · Commits · 戴 / test

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 <b.zolnierkie@samsung.com> Signed-off-by:

Kyungmin Park <kyungmin.park@samsung.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/processor_idle.c

+14 −13

Original line number	Diff line number	Diff line
		@@ -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);

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