PCI: Assign resources before drivers claim devices (pci_scan_root_bus())
Previously, pci_scan_root_bus() created a root PCI bus, enumerated the
devices on it, and called pci_bus_add_devices(), which made the devices
available for drivers to claim them.
Most callers assigned resources to devices after pci_scan_root_bus()
returns, which may be after drivers have claimed the devices. This is
incorrect; the PCI core should not change device resources while a driver
is managing the device.
Remove pci_bus_add_devices() from pci_scan_root_bus() and do it after any
resource assignment in the callers.
Note that ARM's pci_common_init_dev() already called pci_bus_add_devices()
after pci_scan_root_bus(), so we only need to remove the first call:
pci_common_init_dev
pcibios_init_hw
pci_scan_root_bus
pci_bus_add_devices # first call
pci_bus_assign_resources
pci_bus_add_devices # second call
[bhelgaas: changelog, drop "root_bus" var in alpha common_init_pci(),
return failure earlier in mn10300, add "return" in x86 pcibios_scan_root(),
return early if xtensa platform_pcibios_fixup() fails]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
CC: Matt Turner <mattst88@gmail.com>
CC: David Howells <dhowells@redhat.com>
CC: Tony Luck <tony.luck@intel.com>
CC: Michal Simek <monstr@monstr.eu>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Chris Metcalf <cmetcalf@ezchip.com>
CC: Chris Zankel <chris@zankel.net>
CC: Max Filippov <jcmvbkbc@gmail.com>
CC: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/frv/mb93090-mb00/pci-vdk.c b/arch/frv/mb93090-mb00/pci-vdk.c
index b073f4d..f211839 100644
--- a/arch/frv/mb93090-mb00/pci-vdk.c
+++ b/arch/frv/mb93090-mb00/pci-vdk.c
@@ -316,6 +316,7 @@
int __init pcibios_init(void)
{
+ struct pci_bus *bus;
struct pci_ops *dir = NULL;
LIST_HEAD(resources);
@@ -383,12 +384,15 @@
printk("PCI: Probing PCI hardware\n");
pci_add_resource(&resources, &pci_ioport_resource);
pci_add_resource(&resources, &pci_iomem_resource);
- pci_scan_root_bus(NULL, 0, pci_root_ops, NULL, &resources);
+ bus = pci_scan_root_bus(NULL, 0, pci_root_ops, NULL, &resources);
pcibios_irq_init();
pcibios_fixup_irqs();
pcibios_resource_survey();
+ if (!bus)
+ return 0;
+ pci_bus_add_devices(bus);
return 0;
}