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/alpha/kernel/pci.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/alpha') diff --git a/arch/alpha/kernel/pci.c b/arch/alpha/kernel/pci.c index 98a1525fa164..82f738e5d54c 100644 --- a/arch/alpha/kernel/pci.c +++ b/arch/alpha/kernel/pci.c @@ -338,6 +338,8 @@ common_init_pci(void) bus = pci_scan_root_bus(NULL, next_busno, alpha_mv.pci_ops, hose, &resources); + if (!bus) + continue; hose->bus = bus; hose->need_domain_info = need_domain_info; next_busno = bus->busn_res.end + 1; @@ -353,6 +355,11 @@ common_init_pci(void) pci_assign_unassigned_resources(); pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq); + for (hose = hose_head; hose; hose = hose->next) { + bus = hose->bus; + if (bus) + pci_bus_add_devices(bus); + } } -- cgit v1.2.3