| From 47e9037ac16637cd7f12b8790ea7ce6680e42168 Mon Sep 17 00:00:00 2001 |
| From: Stefano Stabellini <stefano.stabellini@eu.citrix.com> |
| Date: Mon, 28 Feb 2011 16:20:11 +0000 |
| Subject: PCI hotplug: acpiphp: set current_state to D0 in register_slot |
| |
| From: Stefano Stabellini <stefano.stabellini@eu.citrix.com> |
| |
| commit 47e9037ac16637cd7f12b8790ea7ce6680e42168 upstream. |
| |
| If a device doesn't support power management (pm_cap == 0) but it is |
| acpi_pci_power_manageable() because there is a _PS0 method declared for |
| it and _EJ0 is also declared for the slot then nobody is going to set |
| current_state = PCI_D0 for this device. This is what I think it is |
| happening: |
| |
| pci_enable_device |
| | |
| __pci_enable_device_flags |
| /* here we do not set current_state because !pm_cap */ |
| | |
| do_pci_enable_device |
| | |
| pci_set_power_state |
| | |
| __pci_start_power_transition |
| | |
| pci_platform_power_transition |
| /* platform_pci_power_manageable() calls acpi_pci_power_manageable that |
| * returns true */ |
| | |
| platform_pci_set_power_state |
| /* acpi_pci_set_power_state gets called and does nothing because the |
| * acpi device has _EJ0, see the comment "If the ACPI device has _EJ0, |
| * ignore the device" */ |
| |
| at this point if we refer to the commit message that introduced the |
| comment above (10b3dcae0f275e2546e55303d64ddbb58cec7599), it is up to |
| the hotplug driver to set the state to D0. |
| However AFAICT the pci hotplug driver never does, in fact |
| drivers/pci/hotplug/acpiphp_glue.c:register_slot sets the slot flags to |
| (SLOT_ENABLED | SLOT_POWEREDON) but it does not set the pci device |
| current state to PCI_D0. |
| |
| So my proposed fix is also to set current_state = PCI_D0 in |
| register_slot. |
| Comments are very welcome. |
| |
| Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> |
| Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/pci/hotplug/acpiphp_glue.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| --- a/drivers/pci/hotplug/acpiphp_glue.c |
| +++ b/drivers/pci/hotplug/acpiphp_glue.c |
| @@ -211,6 +211,7 @@ register_slot(acpi_handle handle, u32 lv |
| |
| pdev = pci_get_slot(pbus, PCI_DEVFN(device, function)); |
| if (pdev) { |
| + pdev->current_state = PCI_D0; |
| slot->flags |= (SLOT_ENABLED | SLOT_POWEREDON); |
| pci_dev_put(pdev); |
| } |