linux-kernel - [PATCH v8 01/13] PCI: do not check is_added flag in pci_remove

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Date:	Tue, 26 Feb 2013 23:25:41 +0800
From:	Jiang Liu <liuj97@...il.com>
To:	Bjorn Helgaas <bhelgaas@...gle.com>,
	"Rafael J . Wysocki" <rjw@...k.pl>
Cc:	Jiang Liu <jiang.liu@...wei.com>, Yinghai Lu <yinghai@...nel.org>,
	Yijing Wang <wangyijing@...wei.com>,
	Jiang Liu <liuj97@...il.com>, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
	Toshi Kani <toshi.kani@...com>,
	Myron Stowe <myron.stowe@...hat.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Subject: [PATCH v8 01/13] PCI: do not check is_added flag in pci_remove_bus()

The is_added flag in struct pci_bus is always set after invoking
device_register() and pci_create_legacy_files(). The related code
paths are:
1) pci_create_root_bus() and pci_add_new_bus()
	bus = pci_alloc_bus()
	device_register(&bus->dev)
	pci_create_legacy_file(bus)
2.a) pci_scan_child_bus(bus)
	set is_added flag for PCI root buses
2.b) pci_bus_add_devices(bus)
	set is_added flag for normal PCI buses

So pci_remove_bus() shouldn't use is_added flag to guard invoking of
pci_remove_lagecy_files() and device_unregister().

One more step further, now bus->is_added is only used to guard invoking
of pcibios_fixup_bus(), so cleaup the code.

Signed-off-by: Jiang Liu <jiang.liu@...wei.com>
Signed-off-by: Yijing Wang <wangyijing@...wei.com>
Cc: Yinghai Lu <yinghai@...nel.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Cc: Toshi Kani <toshi.kani@...com>
Cc: linux-pci@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
---
 drivers/pci/bus.c    |   11 ++---------
 drivers/pci/probe.c  |    3 +--
 drivers/pci/remove.c |    3 ---
 3 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 8647dc6..bdc1e8b 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -206,16 +206,9 @@ void pci_bus_add_devices(const struct pci_bus *bus)
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		BUG_ON(!dev->is_added);
-
 		child = dev->subordinate;
-
-		if (!child)
-			continue;
-		pci_bus_add_devices(child);
-
-		if (child->is_added)
-			continue;
-		child->is_added = 1;
+		if (child)
+			pci_bus_add_devices(child);
 	}
 }
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b494066..45c93b3 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1627,8 +1627,7 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
 	if (!bus->is_added) {
 		dev_dbg(&bus->dev, "fixups for bus\n");
 		pcibios_fixup_bus(bus);
-		if (pci_is_root_bus(bus))
-			bus->is_added = 1;
+		bus->is_added = 1;
 	}
 
 	for (pass=0; pass < 2; pass++)
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index fc38c48..66967e5 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -48,9 +48,6 @@ void pci_remove_bus(struct pci_bus *bus)
 	list_del(&bus->node);
 	pci_bus_release_busn_res(bus);
 	up_write(&pci_bus_sem);
-	if (!bus->is_added)
-		return;
-
 	pci_remove_legacy_files(bus);
 	device_unregister(&bus->dev);
 }
-- 
1.7.9.5

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