From 1d0b19c9a0612c653d1a0df267ba159089f6d139 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Tue, 14 Oct 2008 17:30:05 +0200 Subject: [PATCH] i2c: Guard against oopses from bad init sequences Guard I2C against oopsing because of init sequence problems, by verifying that i2c_init() has been called before calling any routines that rely on that initialization. This specific test just requires that bus_register(&i2c_bus_type) was called. Examples of this kind of oopsing come from subystems and drivers which register I2C drivers in their subsys_initcall code but which are statically linked before I2C by drivers/Makefile. Signed-off-by: David Brownell Signed-off-by: Jean Delvare --- drivers/i2c/i2c-core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index b346a687ab59..a96e1bf27649 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -437,6 +437,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap) { int res = 0, dummy; + /* Can't register until after driver model init */ + if (unlikely(WARN_ON(!i2c_bus_type.p))) + return -EAGAIN; + mutex_init(&adap->bus_lock); mutex_init(&adap->clist_lock); INIT_LIST_HEAD(&adap->clients); @@ -696,6 +700,10 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) { int res; + /* Can't register until after driver model init */ + if (unlikely(WARN_ON(!i2c_bus_type.p))) + return -EAGAIN; + /* new style driver methods can't mix with legacy ones */ if (is_newstyle_driver(driver)) { if (driver->attach_adapter || driver->detach_adapter