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ACPI / hotplug / PCI: Runtime resume bridges before bus rescans

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If a PCI bridge (or PCIe port) that is runtime-suspended gets an ACPI
hotplug notification, such as a bus check, it has to be resumed before
re-scanning the devices below it, or those devices will not be
accessible and will be treated as hot-removed.

Make that happen and let the bridge suspend again after the bus below it
has been re-scanned.

This is a replacement for commit 16468c783c ("ACPI / hotplug / PCI:
Runtime resume bridge before rescan") that has been reverted, because it
introduced a system resume regression (due to missing bridge->pci_dev
checks that are necessary in case the notification is targeted at the
host bridge) and it is necessary for the code added by commit
006d44e49a ("PCI: Add runtime PM support for PCIe ports") to work as
expected.

Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Rafael J. Wysocki 2016-08-05 02:38:44 +02:00 committed by Linus Torvalds
parent f8fbd8c49b
commit dd7fd3a82c
1 changed files with 6 additions and 0 deletions
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6
drivers/pci/hotplug/acpiphp_glue.c
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@ -675,6 +675,9 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
if (bridge->is_going_away) if (bridge->is_going_away)
return; return;
if (bridge->pci_dev)
pm_runtime_get_sync(&bridge->pci_dev->dev);
list_for_each_entry(slot, &bridge->slots, node) { list_for_each_entry(slot, &bridge->slots, node) {
struct pci_bus *bus = slot->bus; struct pci_bus *bus = slot->bus;
struct pci_dev *dev, *tmp; struct pci_dev *dev, *tmp;
@ -694,6 +697,9 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
disable_slot(slot); disable_slot(slot);
} }
} }
if (bridge->pci_dev)
pm_runtime_put(&bridge->pci_dev->dev);
} }
/* /*