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/mn10300/unit-asb2305/pci.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/mn10300/unit-asb2305') diff --git a/arch/mn10300/unit-asb2305/pci.c b/arch/mn10300/unit-asb2305/pci.c index 613ca1e55b4b..3dfe2d31c67b 100644 --- a/arch/mn10300/unit-asb2305/pci.c +++ b/arch/mn10300/unit-asb2305/pci.c @@ -342,6 +342,7 @@ static int __init pcibios_init(void) { resource_size_t io_offset, mem_offset; LIST_HEAD(resources); + struct pci_bus *bus; ioport_resource.start = 0xA0000000; ioport_resource.end = 0xDFFFFFFF; @@ -371,11 +372,14 @@ static int __init pcibios_init(void) pci_add_resource_offset(&resources, &pci_ioport_resource, io_offset); pci_add_resource_offset(&resources, &pci_iomem_resource, mem_offset); - pci_scan_root_bus(NULL, 0, &pci_direct_ampci, NULL, &resources); + bus = pci_scan_root_bus(NULL, 0, &pci_direct_ampci, NULL, &resources); + if (!bus) + return 0; pcibios_irq_init(); pcibios_fixup_irqs(); pcibios_resource_survey(); + pci_bus_add_devices(bus); return 0; } -- cgit