Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi...

[firefly-linux-kernel-4.4.55.git] / drivers / acpi / device_pm.c

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index bc493aa3af19d87e42a18da312815de3c6fbb125..31c217a42839dce40ee2039cd38f36d935bda543 100644 (file)
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -278,16 +278,38 @@ int acpi_bus_init_power(struct acpi_device *device)
                if (result)
                        return result;
        } else if (state == ACPI_STATE_UNKNOWN) {
-               /* No power resources and missing _PSC? Try to force D0. */
+               /*
+                * No power resources and missing _PSC?  Cross fingers and make
+                * it D0 in hope that this is what the BIOS put the device into.
+                * [We tried to force D0 here by executing _PS0, but that broke
+                * Toshiba P870-303 in a nasty way.]
+                */
                state = ACPI_STATE_D0;
-               result = acpi_dev_pm_explicit_set(device, state);
-               if (result)
-                       return result;
        }
        device->power.state = state;
        return 0;
 }
 
+/**
+ * acpi_device_fix_up_power - Force device with missing _PSC into D0.
+ * @device: Device object whose power state is to be fixed up.
+ *
+ * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
+ * are assumed to be put into D0 by the BIOS.  However, in some cases that may
+ * not be the case and this function should be used then.
+ */
+int acpi_device_fix_up_power(struct acpi_device *device)
+{
+       int ret = 0;
+
+       if (!device->power.flags.power_resources
+           && !device->power.flags.explicit_get
+           && device->power.state == ACPI_STATE_D0)
+               ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
+
+       return ret;
+}
+
 int acpi_bus_update_power(acpi_handle handle, int *state_p)
 {
        struct acpi_device *device;