tree 020db9c548090143ffc4fa7f8d808b5c7e3d4eb2
parent e35d8d3cc9242e5323a35b1e05a46b344f573e04
author Luis R. Rodriguez <mcgrof@kernel.org> 1465342890 +0000
committer Luis R. Rodriguez <mcgrof@kernel.org> 1466057133 -0700

i2c: remove __init from i2c_register_board_info()

As of next-20160607 with allyesconfig we get this linker failure:

  MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from
the function intel_scu_devices_create() to the function
.init.text:i2c_register_board_info()

This is caused by the fact that intel_scu_devices_create() calls
i2c_register_board_info() and intel_scu_devices_create() is not
annotated with __init. This typically involves manual code
inspection and if one is certain this is correct we would
just peg intel_scu_devices_create() with a __ref annotation.

In this case this would be wrong though as the
intel_scu_devices_create() call is exported, and used in
the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c.
The issue is that even though builtin_pci_driver(ipc_driver)
is used this just exposes the probe routine, which can occur
at any point in time if this bus supports hotplug. A race
can happen between kernel_init_freeable() that calls the init
calls (in this case registeres the intel_scu_ipc.c driver, and
later free_initmem(), which would free the i2c_register_board_info().
If a probe happens later in boot i2c_register_board_info() would
not be present and we should get a page fault.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>