[PATCH v2 1/1] usb: ulpi: ulpi_init should be executed in subsys_initcall

[Lu Baolu <baolu.lu@linux.intel.com>]

Many drivers and modules depend on ULPI bus registeration to
register ULPI interfaces and drivers. It's more appropriate
to register ULPI bus in subsys_initcall instead of module_init.

Kernel panic has been reported with some kind of kernel config.

[0.746856] kernel BUG at drivers/base/driver.c:153!
[0.752418] invalid opcode: 0000 [#1] PREEMPT SMP
[0.757804] Modules linked in:
[0.893985] Call Trace:
[0.896729]  [<ffffffff81870cb1>] ? ulpi_register_driver+0x21/0x30
[0.903654]  [<ffffffff823d5cac>] tusb1210_driver_init+0x10/0x12
[0.910386]  [<ffffffff81000318>] do_one_initcall+0xd8/0x200
[0.916729]  [<ffffffff8239b094>] kernel_init_freeable+0x196/0x21e
[0.923655]  [<ffffffff81affed0>] ? rest_init+0x90/0x90
[0.929509]  [<ffffffff81affede>] kernel_init+0xe/0xf0
[0.935266]  [<ffffffff81b0f442>] ret_from_fork+0x42/0x70
[0.941315]  [<ffffffff81affed0>] ? rest_init+0x90/0x90

This patch fixes this kind of kernel panic by putting ulpi_init in
subsys_initcall().

Reported-by: Zhuo Qiuxu <qiuxu.zhuo@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/usb/common/ulpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 0e6f968..01c0c04 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -242,7 +242,7 @@ static int __init ulpi_init(void)
 {
 	return bus_register(&ulpi_bus);
 }
-module_init(ulpi_init);
+subsys_initcall(ulpi_init);
 
 static void __exit ulpi_exit(void)
 {
-- 
2.1.4