From: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Date: Tue, 17 Feb 2009 05:13:20 +0000 (+0900)
Subject: PCI hotplug: fix wrong assumption in acpi_get_hp_params_from_firmware
X-Git-Tag: firefly_0821_release~14994^2~53
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=267efd7eec5eca62f32f8c9bc1721b578d5da963;p=firefly-linux-kernel-4.4.55.git

PCI hotplug: fix wrong assumption in acpi_get_hp_params_from_firmware

Current acpi_get_hp_params_from_firmware() has a assumption that
pci_bus->self is NULL on the root pci bus. But it might not true on
some platforms. Because of this wrong assumption, current
acpi_get_hp_params_from_firmware() might cause endless loop. We must
check pci_bus->parent instead.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index f47bc74be567..09a84402986d 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -332,19 +332,14 @@ acpi_status acpi_get_hp_params_from_firmware(struct pci_bus *bus,
 {
 	acpi_status status = AE_NOT_FOUND;
 	acpi_handle handle, phandle;
-	struct pci_bus *pbus = bus;
-	struct pci_dev *pdev;
+	struct pci_bus *pbus;
 
-	do {
-		pdev = pbus->self;
-		if (!pdev) {
-			handle = acpi_get_pci_rootbridge_handle(
-				pci_domain_nr(pbus), pbus->number);
+	handle = NULL;
+	for (pbus = bus; pbus; pbus = pbus->parent) {
+		handle = acpi_pci_get_bridge_handle(pbus);
+		if (handle)
 			break;
-		}
-		handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
-		pbus = pbus->parent;
-	} while (!handle);
+	}
 
 	/*
 	 * _HPP settings apply to all child buses, until another _HPP is