diff options
authorRafael J. Wysocki <>2012-05-18 00:39:35 +0200
committerLinus Torvalds <>2012-05-17 16:16:16 -0700
commit5c7dd710f691d1b44c39e32d2f05b4286ff51f99 (patch)
parenteea036475df8995e5b87cd6b8c8e682e071159cd (diff)
ACPI / PCI / PM: Fix device PM regression related to D3hot/D3cold
Commit 1cc0c998fdf2 ("ACPI: Fix D3hot v D3cold confusion") introduced a bug in __acpi_bus_set_power() and changed the behavior of acpi_pci_set_power_state() in such a way that it generally doesn't work as expected if PCI_D3hot is passed to it as the second argument. First off, if ACPI_STATE_D3 (equal to ACPI_STATE_D3_COLD) is passed to __acpi_bus_set_power() and the explicit_set flag is set for the D3cold state, the function will try to execute AML method called "_PS4", which doesn't exist. Fix this by adding a check to ensure that the name of the AML method to execute for transitions to ACPI_STATE_D3_COLD is correct in __acpi_bus_set_power(). Also make sure that the explicit_set flag for ACPI_STATE_D3_COLD will be set if _PS3 is present and modify acpi_power_transition() to avoid accessing power resources for ACPI_STATE_D3_COLD, because they don't exist. Second, if PCI_D3hot is passed to acpi_pci_set_power_state() as the target state, the function will request a transition to ACPI_STATE_D3_HOT instead of ACPI_STATE_D3. However, ACPI_STATE_D3_HOT is now only marked as supported if the _PR3 AML method is defined for the given device, which is rare. This causes problems to happen on systems where devices were successfully put into ACPI D3 by pci_set_power_state(PCI_D3hot) which doesn't work now. In particular, some unused graphics adapters are not turned off as a result. To fix this issue restore the old behavior of acpi_pci_set_power_state(), which is to request a transition to ACPI_STATE_D3 (equal to ACPI_STATE_D3_COLD) if either PCI_D3hot or PCI_D3cold is passed to it as the argument. This approach is not ideal, because generally power should not be removed from devices if PCI_D3hot is the target power state, but since this behavior is relied on, we have no choice but to restore it at the moment and spend more time on designing a better solution in the future. References: Reported-by: rocko <> Reported-by: Cristian Rodríguez <> Reported-and-tested-by: Peter <> Signed-off-by: Rafael J. Wysocki <> Signed-off-by: Linus Torvalds <>
4 files changed, 15 insertions, 4 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3263b68cdfa3..3188da3df8da 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -250,6 +250,10 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
return -ENODEV;
+ /* For D3cold we should execute _PS3, not _PS4. */
+ if (state == ACPI_STATE_D3_COLD)
+ object_name[3] = '3';
* Transition Power
* ----------------
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 330bb4d75852..0500f719f63e 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -660,7 +660,7 @@ int acpi_power_on_resources(struct acpi_device *device, int state)
int acpi_power_transition(struct acpi_device *device, int state)
- int result;
+ int result = 0;
if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
@@ -679,8 +679,11 @@ int acpi_power_transition(struct acpi_device *device, int state)
* (e.g. so the device doesn't lose power while transitioning). Then,
* we dereference all power resources used in the current list.
- result = acpi_power_on_list(&device->power.states[state].resources);
- if (!result)
+ if (state < ACPI_STATE_D3_COLD)
+ result = acpi_power_on_list(
+ &device->power.states[state].resources);
+ if (!result && device->power.state < ACPI_STATE_D3_COLD)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7417267e88fa..85cbfdccc97c 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -908,6 +908,10 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
device->power.states[ACPI_STATE_D3].flags.valid = 1;
device->power.states[ACPI_STATE_D3].power = 0;
+ /* Set D3cold's explicit_set flag if _PS3 exists. */
+ if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
+ device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
return 0;
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 1929c0c63b75..61e2fefeedab 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -223,7 +223,7 @@ static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
- [PCI_D3hot] = ACPI_STATE_D3_HOT,
+ [PCI_D3hot] = ACPI_STATE_D3,
[PCI_D3cold] = ACPI_STATE_D3
int error = -EINVAL;