Re: [PATCH] net: mdio-octeon: Add PCI driver binding.

[David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>]

From: David Daney <ddaney.cavm@gmail.com>
Date: Tue, 22 Sep 2015 17:41:36 -0700

> From: David Daney <david.daney@cavium.com>
> 
> When the Cavium mdio-octeon devices appear in the Thunder family of
> arm64 based SoCs, they show up as PCI devices.  Add PCI driver
> wrapping so the driver is bound in the standard PCI device scan.
> 
> When in this form, a single PCI device may have more than a single
> bus, we call this a "nexus" of buses.  The standard firmware
> device_for_each_child_node() iterator is used to find the individual
> buses underneath the "nexus".
> 
> Update the device tree binding documentation for the new PCI driver
> binding.
> 
> Signed-off-by: David Daney <david.daney@cavium.com>

This patch breaks the build:

  CC [M]  drivers/net/phy/mdio-octeon.o
In file included from drivers/net/phy/mdio-octeon.c:13:0:
include/linux/module.h:128:27: error: redefinition of ‘__inittest’
  static inline initcall_t __inittest(void)  \
                           ^
include/linux/device.h:1321:1: note: in expansion of macro ‘module_init’
 module_init(__driver##_init); \
 ^
include/linux/pci.h:1192:2: note: in expansion of macro ‘module_driver’
  module_driver(__pci_driver, pci_register_driver, \
  ^
drivers/net/phy/mdio-octeon.c:513:1: note: in expansion of macro ‘module_pci_driver’
 module_pci_driver(thunder_mdiobus_driver);
 ^
include/linux/module.h:128:27: note: previous definition of ‘__inittest’ was here
  static inline initcall_t __inittest(void)  \
                           ^
include/linux/device.h:1321:1: note: in expansion of macro ‘module_init’
 module_init(__driver##_init); \
 ^
include/linux/platform_device.h:222:2: note: in expansion of macro ‘module_driver’
  module_driver(__platform_driver, platform_driver_register, \
  ^
drivers/net/phy/mdio-octeon.c:373:1: note: in expansion of macro ‘module_platform_driver’
 module_platform_driver(octeon_mdiobus_driver);
 ^
include/linux/module.h:130:6: error: redefinition of ‘init_module’
  int init_module(void) __attribute__((alias(#initfn)));
      ^
include/linux/device.h:1321:1: note: in expansion of macro ‘module_init’
 module_init(__driver##_init); \
 ^
include/linux/pci.h:1192:2: note: in expansion of macro ‘module_driver’
  module_driver(__pci_driver, pci_register_driver, \
  ^
drivers/net/phy/mdio-octeon.c:513:1: note: in expansion of macro ‘module_pci_driver’
 module_pci_driver(thunder_mdiobus_driver);
 ^
include/linux/module.h:130:6: note: previous definition of ‘init_module’ was here
  int init_module(void) __attribute__((alias(#initfn)));
      ^
include/linux/device.h:1321:1: note: in expansion of macro ‘module_init’
 module_init(__driver##_init); \
 ^
include/linux/platform_device.h:222:2: note: in expansion of macro ‘module_driver’
  module_driver(__platform_driver, platform_driver_register, \
  ^
drivers/net/phy/mdio-octeon.c:373:1: note: in expansion of macro ‘module_platform_driver’
 module_platform_driver(octeon_mdiobus_driver);
 ^
include/linux/module.h:134:27: error: redefinition of ‘__exittest’
  static inline exitcall_t __exittest(void)  \
                           ^
include/linux/device.h:1326:1: note: in expansion of macro ‘module_exit’
 module_exit(__driver##_exit);
 ^
include/linux/pci.h:1192:2: note: in expansion of macro ‘module_driver’
  module_driver(__pci_driver, pci_register_driver, \
  ^
drivers/net/phy/mdio-octeon.c:513:1: note: in expansion of macro ‘module_pci_driver’
 module_pci_driver(thunder_mdiobus_driver);
 ^
include/linux/module.h:134:27: note: previous definition of ‘__exittest’ was here
  static inline exitcall_t __exittest(void)  \
                           ^
include/linux/device.h:1326:1: note: in expansion of macro ‘module_exit’
 module_exit(__driver##_exit);
 ^
include/linux/platform_device.h:222:2: note: in expansion of macro ‘module_driver’
  module_driver(__platform_driver, platform_driver_register, \
  ^
drivers/net/phy/mdio-octeon.c:373:1: note: in expansion of macro ‘module_platform_driver’
 module_platform_driver(octeon_mdiobus_driver);
 ^
include/linux/module.h:136:7: error: redefinition of ‘cleanup_module’
  void cleanup_module(void) __attribute__((alias(#exitfn)));
       ^
include/linux/device.h:1326:1: note: in expansion of macro ‘module_exit’
 module_exit(__driver##_exit);
 ^
include/linux/pci.h:1192:2: note: in expansion of macro ‘module_driver’
  module_driver(__pci_driver, pci_register_driver, \
  ^
drivers/net/phy/mdio-octeon.c:513:1: note: in expansion of macro ‘module_pci_driver’
 module_pci_driver(thunder_mdiobus_driver);
 ^
include/linux/module.h:136:7: note: previous definition of ‘cleanup_module’ was here
  void cleanup_module(void) __attribute__((alias(#exitfn)));
       ^
include/linux/device.h:1326:1: note: in expansion of macro ‘module_exit’
 module_exit(__driver##_exit);
 ^
include/linux/platform_device.h:222:2: note: in expansion of macro ‘module_driver’
  module_driver(__platform_driver, platform_driver_register, \
  ^
drivers/net/phy/mdio-octeon.c:373:1: note: in expansion of macro ‘module_platform_driver’
 module_platform_driver(octeon_mdiobus_driver);
 ^

And frankly I'm not sure I like this change anyways.  If the OF nodes
are there, simply add code to match on those OF nodes.

This is better than assuming what sits underneath a PCI node, without
any checks for the 'name' or 'compatible' properties at all.  That's
what they are there for afterall.