From b97ea289cf6aff8d4cbcefe2b707bb9b00a73c73 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Mon, 16 Mar 2015 11:18:56 +0800 Subject: 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 Signed-off-by: Bjorn Helgaas CC: Richard Henderson CC: Ivan Kokshaysky CC: Matt Turner CC: David Howells CC: Tony Luck CC: Michal Simek CC: Ralf Baechle CC: Koichi Yasutake CC: Sebastian Ott CC: "David S. Miller" CC: Chris Metcalf CC: Chris Zankel CC: Max Filippov CC: Thomas Gleixner --- arch/frv/mb93090-mb00/pci-vdk.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/frv') diff --git a/arch/frv/mb93090-mb00/pci-vdk.c b/arch/frv/mb93090-mb00/pci-vdk.c index b073f4d771a5..f211839e2cae 100644 --- a/arch/frv/mb93090-mb00/pci-vdk.c +++ b/arch/frv/mb93090-mb00/pci-vdk.c @@ -316,6 +316,7 @@ void pcibios_fixup_bus(struct pci_bus *bus) int __init pcibios_init(void) { + struct pci_bus *bus; struct pci_ops *dir = NULL; LIST_HEAD(resources); @@ -383,12 +384,15 @@ int __init pcibios_init(void) 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; } -- cgit v1.2.3