From 25eed40720fc9005c63a1f436e5f8a78836c26ff Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 25 Nov 2010 00:09:15 +0100 Subject: ACPI / PM: Add function for updating device power state consistently Add function acpi_bus_update_power() for reading the actual power state of an ACPI device and updating its device->power.state field in such a way that its power resources' reference counters will remain consistent with that field. For this purpose introduce __acpi_bus_set_power() setting the power state of an ACPI device without updating its device->power.state field and make acpi_bus_set_power() and acpi_bus_update_power() use it (acpi_bus_set_power() retains the current behavior for now). Signed-off-by: Rafael J. Wysocki Signed-off-by: Len Brown --- drivers/acpi/bus.c | 90 ++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 61 insertions(+), 29 deletions(-) (limited to 'drivers/acpi/bus.c') diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 453451090502..19decee72e92 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -255,44 +255,17 @@ int acpi_bus_get_power(acpi_handle handle, int *state) EXPORT_SYMBOL(acpi_bus_get_power); -int acpi_bus_set_power(acpi_handle handle, int state) +static int __acpi_bus_set_power(struct acpi_device *device, int state) { int result = 0; acpi_status status = AE_OK; - struct acpi_device *device = NULL; char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' }; - - result = acpi_bus_get_device(handle, &device); - if (result) - return result; - - if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3)) + if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3)) return -EINVAL; /* Make sure this is a valid target state */ - if (!device->flags.power_manageable) { - ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n", - kobject_name(&device->dev.kobj))); - return -ENODEV; - } - /* - * Get device's current power state - */ - if (!acpi_power_nocheck) { - /* - * Maybe the incorrect power state is returned on the bogus - * bios, which is different with the real power state. - * For example: the bios returns D0 state and the real power - * state is D3. OS expects to set the device to D0 state. In - * such case if OS uses the power state returned by the BIOS, - * the device can't be transisted to the correct power state. - * So if the acpi_power_nocheck is set, it is unnecessary to - * get the power state by calling acpi_bus_get_power. - */ - acpi_bus_get_power(device->handle, &device->power.state); - } if ((state == device->power.state) && !device->flags.force_power_state) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n", state)); @@ -362,6 +335,42 @@ int acpi_bus_set_power(acpi_handle handle, int state) return result; } + +int acpi_bus_set_power(acpi_handle handle, int state) +{ + struct acpi_device *device; + int result; + + result = acpi_bus_get_device(handle, &device); + if (result) + return result; + + if (!device->flags.power_manageable) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Device [%s] is not power manageable\n", + dev_name(&device->dev))); + return -ENODEV; + } + + /* + * Get device's current power state + */ + if (!acpi_power_nocheck) { + /* + * Maybe the incorrect power state is returned on the bogus + * bios, which is different with the real power state. + * For example: the bios returns D0 state and the real power + * state is D3. OS expects to set the device to D0 state. In + * such case if OS uses the power state returned by the BIOS, + * the device can't be transisted to the correct power state. + * So if the acpi_power_nocheck is set, it is unnecessary to + * get the power state by calling acpi_bus_get_power. + */ + __acpi_bus_get_power(device, &device->power.state); + } + + return __acpi_bus_set_power(device, state); +} EXPORT_SYMBOL(acpi_bus_set_power); @@ -389,6 +398,29 @@ int acpi_bus_init_power(struct acpi_device *device) } +int acpi_bus_update_power(acpi_handle handle, int *state_p) +{ + struct acpi_device *device; + int state; + int result; + + result = acpi_bus_get_device(handle, &device); + if (result) + return result; + + result = __acpi_bus_get_power(device, &state); + if (result) + return result; + + result = __acpi_bus_set_power(device, state); + if (!result && state_p) + *state_p = state; + + return result; +} +EXPORT_SYMBOL_GPL(acpi_bus_update_power); + + bool acpi_bus_power_manageable(acpi_handle handle) { struct acpi_device *device; -- cgit v1.2.3