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>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
index 6cc78c213c01..24384e1dc33d 100644
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -391,12 +391,16 @@ static void __init pcic_pbm_scan_bus(struct linux_pcic *pcic)
         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);
 }
 
 /*