From d5eefa8280a8bb1e8aef059154bc1d63e1ac3336 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 21 May 2015 04:19:49 +0200 Subject: [PATCH] ACPI / PM: Turn power resources on and off in the right order during resume According to Section 7.2 of ACPI 6.0, power resources should always be enabled and disabled in order given by the "resourceorder" field of the corresponding Power Resource objects: "Power Resource levels are enabled from low values to high values and are disabled from high values to low values." However, this is not what happens during system resume, because in that case the enabling/disabling is carried out in the power resource registration order which may not reflect the ordering required by the platform. For this reason, make the ordering of the global list of all power resources in the system (used by the system resume code) reflect the one given by the "resourceorder" attributes of the Power Resource objects in the ACPI namespace and modify acpi_resume_power_resources() to walk the list in the reverse order when turning off the power resources that had been off before the system was suspended. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/power.c | 40 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 1f8138f24d72..93eac53b5110 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -760,6 +760,25 @@ static void acpi_power_sysfs_remove(struct acpi_device *device) device_remove_file(&device->dev, &dev_attr_resource_in_use); } +static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource) +{ + mutex_lock(&power_resource_list_lock); + + if (!list_empty(&acpi_power_resource_list)) { + struct acpi_power_resource *r; + + list_for_each_entry(r, &acpi_power_resource_list, list_node) + if (r->order > resource->order) { + list_add_tail(&resource->list_node, &r->list_node); + goto out; + } + } + list_add_tail(&resource->list_node, &acpi_power_resource_list); + + out: + mutex_unlock(&power_resource_list_lock); +} + int acpi_add_power_resource(acpi_handle handle) { struct acpi_power_resource *resource; @@ -810,9 +829,7 @@ int acpi_add_power_resource(acpi_handle handle) if (!device_create_file(&device->dev, &dev_attr_resource_in_use)) device->remove = acpi_power_sysfs_remove; - mutex_lock(&power_resource_list_lock); - list_add(&resource->list_node, &acpi_power_resource_list); - mutex_unlock(&power_resource_list_lock); + acpi_power_add_resource_to_list(resource); acpi_device_add_finalize(device); return 0; @@ -843,7 +860,22 @@ void acpi_resume_power_resources(void) && resource->ref_count) { dev_info(&resource->device.dev, "Turning ON\n"); __acpi_power_on(resource); - } else if (state == ACPI_POWER_RESOURCE_STATE_ON + } + + mutex_unlock(&resource->resource_lock); + } + list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) { + int result, state; + + mutex_lock(&resource->resource_lock); + + result = acpi_power_get_state(resource->device.handle, &state); + if (result) { + mutex_unlock(&resource->resource_lock); + continue; + } + + if (state == ACPI_POWER_RESOURCE_STATE_ON && !resource->ref_count) { dev_info(&resource->device.dev, "Turning OFF\n"); __acpi_power_off(resource);