From dd7fd3a82ce55e5772d41b1faa2439f15318a902 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 5 Aug 2016 02:38:44 +0200 Subject: [PATCH] ACPI / hotplug / PCI: Runtime resume bridges before bus rescans 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 16468c783cb4 ("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 006d44e49a25 ("PCI: Add runtime PM support for PCIe ports") to work as expected. Tested-by: Linus Torvalds Signed-off-by: Rafael J. Wysocki Signed-off-by: Linus Torvalds --- drivers/pci/hotplug/acpiphp_glue.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index fa49f9143b80..a46b585fae31 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -675,6 +675,9 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge) if (bridge->is_going_away) return; + if (bridge->pci_dev) + pm_runtime_get_sync(&bridge->pci_dev->dev); + list_for_each_entry(slot, &bridge->slots, node) { struct pci_bus *bus = slot->bus; struct pci_dev *dev, *tmp; @@ -694,6 +697,9 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge) disable_slot(slot); } } + + if (bridge->pci_dev) + pm_runtime_put(&bridge->pci_dev->dev); } /* -- 2.20.1