On 17/05/12 18:39, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki<rjw@xxxxxxx> 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-and-tested-by: Peter<lekensteyn@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki<rjw@xxxxxxx> ---
Ok, tested this one in the affected box, it works. echo OFF > /sys/kernel/debug/vgaswitcheroo/switch [ 77.436767] VGA switcheroo: switched nouveau off [ 77.437004] [drm] nouveau 0000:01:00.0: Disabling display... [ 77.437110] [drm] nouveau 0000:01:00.0: Disabling fbcon... [ 77.437113] [drm] nouveau 0000:01:00.0: Unpinning framebuffer(s)... [ 77.437157] [drm] nouveau 0000:01:00.0: Evicting buffers... [ 77.439175] [drm] nouveau 0000:01:00.0: Idling channels... [ 77.439316] [drm] nouveau 0000:01:00.0: Suspending GPU objects... [ 77.771133] [drm] nouveau 0000:01:00.0: And we're gone! [ 78.082258] nouveau 0000:01:00.0: power state changed by ACPI to D3 laptop's fan is silent again :-) , thanks for fixing it ! -- 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
