---

yaml
---
r: 117283
b: refs/heads/master
c: f5adfaa
h: refs/heads/master
i:
  117281: 129a030
  117279: 68e3a8e
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: eab4b645769fa2f8703f5a3cb0cc4ac090d347af
+refs/heads/master: f5adfaa372c76423b6e8e4727a9701330374f364

trunk/Documentation/kernel-parameters.txt

@@ -251,6 +251,14 @@ and is between 256 and 4096 characters. It is defined in the file
  			Warning: Many of these options can produce a lot of
  			output and make your system unusable. Be very careful.
 
+ 	acpi.power_nocheck=	[HW,ACPI]
+ 			Format: 1/0 enable/disable the check of power state.
+ 			On some bogus BIOS the _PSC object/_STA object of
+ 			power resource can't return the correct device power
+ 			state. In such case it is unneccessary to check its
+ 			power state again in power transition.
+ 			1 : disable the power state check
+
 	acpi_pm_good	[X86-32,X86-64]
 			Override the pmtimer bug detection: force the kernel
 			to assume that this machine's pmtimer latches its value

trunk/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));

trunk/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;

trunk/include/acpi/acpi_drivers.h

@@ -93,6 +93,7 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state);
 int acpi_disable_wakeup_device_power(struct acpi_device *dev);
 int acpi_power_get_inferred_state(struct acpi_device *device);
 int acpi_power_transition(struct acpi_device *device, int state);
+extern int acpi_power_nocheck;
 #endif
 
 /* --------------------------------------------------------------------------