diff options
Diffstat (limited to 'drivers/acpi/bus.c')
| -rw-r--r-- | drivers/acpi/bus.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index ccae305ee55d..91bdeb3b081e 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -223,7 +223,19 @@ int acpi_bus_set_power(acpi_handle handle, int state) /* * Get device's current power state */ - acpi_bus_get_power(device->handle, &device->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)); |