From 5c7dd710f691d1b44c39e32d2f05b4286ff51f99 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 18 May 2012 00:39:35 +0200 Subject: ACPI / PCI / PM: Fix device PM regression related to D3hot/D3cold MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: https://bugzilla.kernel.org/show_bug.cgi?id=43228 Reported-by: rocko Reported-by: Cristian Rodríguez Reported-and-tested-by: Peter Signed-off-by: Rafael J. Wysocki Signed-off-by: Linus Torvalds --- drivers/pci/pci-acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/pci-acpi.c') 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_D0] = ACPI_STATE_D0, [PCI_D1] = ACPI_STATE_D1, [PCI_D2] = ACPI_STATE_D2, - [PCI_D3hot] = ACPI_STATE_D3_HOT, + [PCI_D3hot] = ACPI_STATE_D3, [PCI_D3cold] = ACPI_STATE_D3 }; int error = -EINVAL; -- cgit v1.2.3-59-g8ed1b