From: Rafael J. Wysocki <rjw@xxxxxxx> Subject: ACPI / PCI / PM: Fix device PM regression related to D3hot/D3cold Commit 1cc0c998fdf2cb665d625fb565a0d6db5c81c639 (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 <rockorequin@xxxxxxxxxxx> Reported-by: Cristian Rodríguez <crrodriguez@xxxxxxxxxxxx> Reported-by: Peter <lekensteyn@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- Well, one more update today. It turns out that in some cases devices are transitioned to D3(cold) directly from ACPI_STATE_UNKNOWN (255), so we need to make sure that _PS3 is called in those cases too. Please test! Thanks, Rafael --- drivers/acpi/bus.c | 4 ++++ drivers/acpi/power.c | 9 ++++++--- drivers/acpi/scan.c | 4 ++++ drivers/pci/pci-acpi.c | 2 +- 4 files changed, 15 insertions(+), 4 deletions(-) Index: linux/drivers/pci/pci-acpi.c =================================================================== --- linux.orig/drivers/pci/pci-acpi.c +++ linux/drivers/pci/pci-acpi.c @@ -223,7 +223,7 @@ static int acpi_pci_set_power_state(stru [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; Index: linux/drivers/acpi/bus.c =================================================================== --- linux.orig/drivers/acpi/bus.c +++ linux/drivers/acpi/bus.c @@ -250,6 +250,10 @@ static int __acpi_bus_set_power(struct a return -ENODEV; } + /* For D3cold we should execute _PS3, not _PS4. */ + if (state == ACPI_STATE_D3_COLD) + object_name[3] = '3'; + /* * Transition Power * ---------------- Index: linux/drivers/acpi/scan.c =================================================================== --- linux.orig/drivers/acpi/scan.c +++ linux/drivers/acpi/scan.c @@ -908,6 +908,10 @@ static int acpi_bus_get_power_flags(stru 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; + acpi_bus_init_power(device); return 0; Index: linux/drivers/acpi/power.c =================================================================== --- linux.orig/drivers/acpi/power.c +++ linux/drivers/acpi/power.c @@ -660,7 +660,7 @@ int acpi_power_on_resources(struct acpi_ 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_de * (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) acpi_power_off_list( &device->power.states[device->power.state].resources); -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
