[PATCH v8 01/13] PCI: do not check is_added flag in pci_remove_bus()

From: Jiang Liu
Date: Tue Feb 26 2013 - 10:30:44 EST


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@xxxxxxxxxx>
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
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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