Pci_bus_add_devices() should not be placed in pci_scan_bus().
Now pci device will be added to driver core once its
creation. All things left in pci_bus_add_devices() are
driver attachment and other trivial sysfs things.
Pci_scan_bus() should be the function responsible for
scanning PCI devices, not including driver attachment.
Other, some callers(m68k,unicore32,alpha) of pci_scan_bus()
will call pci_bus_size_bridges() and pci_bus_assign_resources()
after pci_scan_bus().

E.g.
In m68k
mcf_pci_init()
        pci_scan_bus()
                ...
                pci_bus_add_devices() --- try to attach driver
        pci_fixup_irqs()
        pci_bus_size_bridges()
        pci_bus_assign_resources()

It is not correct, resources should be assigned correctly
before attaching driver.
So we should rip out pci_bus_add_devices() for better
code design. After applied this patch, pci_scan_bus()
should be used in flow like:

pci_scan_bus() (mandatory)
pci_fixup_irqs() (optional)
pci_bus_size_bridges() (optional)
pci_pci_bus_assign_resources() (optional)
pci_bus_add_devices() (mandatory)

Signed-off-by: Yijing Wang <wangyij...@huawei.com>
CC: "David S. Miller" <da...@davemloft.net>
CC: Geert Uytterhoeven <ge...@linux-m68k.org>
CC: Guan Xuetao <g...@mprc.pku.edu.cn>
CC: linux-al...@vger.kernel.org
CC: linux-m...@lists.linux-m68k.org
CC: sparcli...@vger.kernel.org
---
 arch/alpha/kernel/sys_nautilus.c  |    1 +
 arch/m68k/coldfire/pci.c          |    1 +
 arch/sparc/kernel/pcic.c          |    2 ++
 arch/unicore32/kernel/pci.c       |   11 +++--------
 drivers/pci/hotplug/ibmphp_core.c |    6 ++++--
 drivers/pci/probe.c               |    1 -
 6 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c
index 837c0fa..4ae4a40 100644
--- a/arch/alpha/kernel/sys_nautilus.c
+++ b/arch/alpha/kernel/sys_nautilus.c
@@ -253,6 +253,7 @@ nautilus_init_pci(void)
           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..d45f087 100644
--- a/arch/m68k/coldfire/pci.c
+++ b/arch/m68k/coldfire/pci.c
@@ -319,6 +319,7 @@ static int __init mcf_pci_init(void)
        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..7a82fe2 100644
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -391,6 +391,8 @@ 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)
+               pci_bus_add_devices(pbm->pci_bus);
 #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);
diff --git a/arch/unicore32/kernel/pci.c b/arch/unicore32/kernel/pci.c
index 374a055..3d82024 100644
--- a/arch/unicore32/kernel/pci.c
+++ b/arch/unicore32/kernel/pci.c
@@ -266,17 +266,12 @@ static int __init pci_common_init(void)
        pci_fixup_irqs(pci_common_swizzle, pci_puv3_map_irq);
 
        if (!pci_has_flag(PCI_PROBE_ONLY)) {
-               /*
-                * Size the bridge windows.
-                */
+               /* Size the bridge windows. */
                pci_bus_size_bridges(puv3_bus);
-
-               /*
-                * Assign resources.
-                */
+               /* Assign resources. */
                pci_bus_assign_resources(puv3_bus);
        }
-
+       pci_bus_add_devices(puv3_bus);
        return 0;
 }
 subsys_initcall(pci_common_init);
diff --git a/drivers/pci/hotplug/ibmphp_core.c 
b/drivers/pci/hotplug/ibmphp_core.c
index 96c5c72..86e3bfd 100644
--- a/drivers/pci/hotplug/ibmphp_core.c
+++ b/drivers/pci/hotplug/ibmphp_core.c
@@ -738,7 +738,7 @@ static void ibm_unconfigure_device(struct pci_func *func)
  */
 static u8 bus_structure_fixup(u8 busno)
 {
-       struct pci_bus *bus;
+       struct pci_bus *bus, *b;
        struct pci_dev *dev;
        u16 l;
 
@@ -765,7 +765,9 @@ static u8 bus_structure_fixup(u8 busno)
                                        (l != 0x0000) && (l != 0xffff)) {
                        debug("%s - Inside bus_structure_fixup()\n",
                                                        __func__);
-                       pci_scan_bus(busno, ibmphp_pci_bus->ops, NULL);
+                       b = pci_scan_bus(busno, ibmphp_pci_bus->ops, NULL);
+                       if (b)
+                               pci_bus_add_devices(b);
                        break;
                }
        }
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 23212f8..053c0f4 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2123,7 +2123,6 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
        b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
        if (b) {
                pci_scan_child_bus(b);
-               pci_bus_add_devices(b);
        } else {
                pci_free_resource_list(&resources);
        }
-- 
1.7.1

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