PCI: Assign resources before drivers claim devices (pci_scan_bus())
Previously, pci_scan_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_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_bus() and do it after any
resource assignment in the callers.
[bhelgaas: changelog, check for failure in mcf_pci_init()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Guan Xuetao <gxt@mprc.pku.edu.cn>
CC: Richard Henderson <rth@twiddle.net>
CC: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
CC: Matt Turner <mattst88@gmail.com>
diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c
index 837c0fa..700686d 100644
--- a/arch/alpha/kernel/sys_nautilus.c
+++ b/arch/alpha/kernel/sys_nautilus.c
@@ -207,6 +207,9 @@
/* Scan our single hose. */
bus = pci_scan_bus(0, alpha_mv.pci_ops, hose);
+ if (!bus)
+ return;
+
hose->bus = bus;
pcibios_claim_one_bus(bus);
@@ -253,6 +256,7 @@
for the root bus, so just clear it. */
bus->self = NULL;
pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq);
+ pci_bus_add_devices(bus);
}
/*
diff --git a/arch/m68k/coldfire/pci.c b/arch/m68k/coldfire/pci.c
index df96792..821de92 100644
--- a/arch/m68k/coldfire/pci.c
+++ b/arch/m68k/coldfire/pci.c
@@ -313,12 +313,16 @@
schedule_timeout(msecs_to_jiffies(200));
rootbus = pci_scan_bus(0, &mcf_pci_ops, NULL);
+ if (!rootbus)
+ return -ENODEV;
+
rootbus->resource[0] = &mcf_pci_io;
rootbus->resource[1] = &mcf_pci_mem;
pci_fixup_irqs(pci_common_swizzle, mcf_pci_map_irq);
pci_bus_size_bridges(rootbus);
pci_bus_assign_resources(rootbus);
+ pci_bus_add_devices(rootbus);
return 0;
}
diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
index 6cc78c2..24384e1 100644
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -391,12 +391,16 @@
struct linux_pbm_info *pbm = &pcic->pbm;
pbm->pci_bus = pci_scan_bus(pbm->pci_first_busno, &pcic_ops, pbm);
+ if (!pbm->pci_bus)
+ return;
+
#if 0 /* deadwood transplanted from sparc64 */
pci_fill_in_pbm_cookies(pbm->pci_bus, pbm, pbm->prom_node);
pci_record_assignments(pbm, pbm->pci_bus);
pci_assign_unassigned(pbm, pbm->pci_bus);
pci_fixup_irq(pbm, pbm->pci_bus);
#endif
+ pci_bus_add_devices(pbm->pci_bus);
}
/*
diff --git a/arch/unicore32/kernel/pci.c b/arch/unicore32/kernel/pci.c
index 374a055..d45fa5f 100644
--- a/arch/unicore32/kernel/pci.c
+++ b/arch/unicore32/kernel/pci.c
@@ -266,17 +266,10 @@
pci_fixup_irqs(pci_common_swizzle, pci_puv3_map_irq);
if (!pci_has_flag(PCI_PROBE_ONLY)) {
- /*
- * Size the bridge windows.
- */
pci_bus_size_bridges(puv3_bus);
-
- /*
- * Assign resources.
- */
pci_bus_assign_resources(puv3_bus);
}
-
+ pci_bus_add_devices(puv3_bus);
return 0;
}
subsys_initcall(pci_common_init);