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| author |   David Brownell <dbrownell@users.sourceforge.net> | 2008-10-14 17:30:05 +0200 |
|---|---|---|
| committer |   Jean Delvare <khali@mahadeva.delvare> | 2008-10-14 17:30:05 +0200 |
| commit | 1d0b19c9a0612c653d1a0df267ba159089f6d139 (patch) | |
| tree | 406b09500a13eaf91f2f8a925e76db40f450a712 /drivers/i2c | |
| parent | i2c: Document the implementation details of the /dev interface (diff) | |
| download | linux-dev-1d0b19c9a0612c653d1a0df267ba159089f6d139.tar.xz linux-dev-1d0b19c9a0612c653d1a0df267ba159089f6d139.zip | |
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 <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 8 |
1 files changed, 8 insertions, 0 deletions
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 |