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Commit 1d0b19c9 authored by David Brownell's avatar David Brownell Committed by Jean Delvare
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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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 7c15fd12

drivers/i2c/i2c-core.c

+8 −0
Original line number Diff line number Diff line
@@ -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