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-rw-r--r--drivers/acpi/bus.c14
-rw-r--r--drivers/acpi/power.c42
2 files changed, 44 insertions, 12 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index ccae305ee55..91bdeb3b081 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));
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index e7bab75075a..7ff7349c0c5 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -54,6 +54,14 @@ ACPI_MODULE_NAME("power");
#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
#define ACPI_POWER_RESOURCE_STATE_ON 0x01
#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
+
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "acpi."
+int acpi_power_nocheck;
+module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
+
static int acpi_power_add(struct acpi_device *device);
static int acpi_power_remove(struct acpi_device *device, int type);
static int acpi_power_resume(struct acpi_device *device);
@@ -228,12 +236,18 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
if (ACPI_FAILURE(status))
return -ENODEV;
- result = acpi_power_get_state(resource->device->handle, &state);
- if (result)
- return result;
- if (state != ACPI_POWER_RESOURCE_STATE_ON)
- return -ENOEXEC;
-
+ if (!acpi_power_nocheck) {
+ /*
+ * If acpi_power_nocheck is set, it is unnecessary to check
+ * the power state after power transition.
+ */
+ result = acpi_power_get_state(resource->device->handle,
+ &state);
+ if (result)
+ return result;
+ if (state != ACPI_POWER_RESOURCE_STATE_ON)
+ return -ENOEXEC;
+ }
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D0;
@@ -279,11 +293,17 @@ static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
if (ACPI_FAILURE(status))
return -ENODEV;
- result = acpi_power_get_state(handle, &state);
- if (result)
- return result;
- if (state != ACPI_POWER_RESOURCE_STATE_OFF)
- return -ENOEXEC;
+ if (!acpi_power_nocheck) {
+ /*
+ * If acpi_power_nocheck is set, it is unnecessary to check
+ * the power state after power transition.
+ */
+ result = acpi_power_get_state(handle, &state);
+ if (result)
+ return result;
+ if (state != ACPI_POWER_RESOURCE_STATE_OFF)
+ return -ENOEXEC;
+ }
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D3;