diff options
| -rw-r--r-- | drivers/i2c/i2c-core.c | 51 |
1 files changed, 28 insertions, 23 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index b1fd00d9a5c..a2f1cd3766f 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -38,6 +38,9 @@ #include "i2c-core.h" +/* core_lock protects i2c_adapter_idr, and guarantees + that device detection, deletion of detected devices, and attach_adapter + and detach_adapter calls are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); @@ -418,13 +421,13 @@ 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; + if (unlikely(WARN_ON(!i2c_bus_type.p))) { + res = -EAGAIN; + goto out_list; + } mutex_init(&adap->bus_lock); - mutex_lock(&core_lock); - /* Set default timeout to 1 second if not already set */ if (adap->timeout == 0) adap->timeout = HZ; @@ -443,16 +446,18 @@ static int i2c_register_adapter(struct i2c_adapter *adap) i2c_scan_static_board_info(adap); /* Notify drivers */ + mutex_lock(&core_lock); dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, i2c_do_add_adapter); - -out_unlock: mutex_unlock(&core_lock); - return res; + + return 0; out_list: + mutex_lock(&core_lock); idr_remove(&i2c_adapter_idr, adap->nr); - goto out_unlock; + mutex_unlock(&core_lock); + return res; } /** @@ -590,22 +595,25 @@ static int __unregister_client(struct device *dev, void *dummy) int i2c_del_adapter(struct i2c_adapter *adap) { int res = 0; - - mutex_lock(&core_lock); + struct i2c_adapter *found; /* First make sure that this adapter was ever added */ - if (idr_find(&i2c_adapter_idr, adap->nr) != adap) { + mutex_lock(&core_lock); + found = idr_find(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); + if (found != adap) { pr_debug("i2c-core: attempting to delete unregistered " "adapter [%s]\n", adap->name); - res = -EINVAL; - goto out_unlock; + return -EINVAL; } /* Tell drivers about this removal */ + mutex_lock(&core_lock); res = bus_for_each_drv(&i2c_bus_type, NULL, adap, i2c_do_del_adapter); + mutex_unlock(&core_lock); if (res) - goto out_unlock; + return res; /* Detach any active clients. This can't fail, thus we do not checking the returned value. */ @@ -619,7 +627,9 @@ int i2c_del_adapter(struct i2c_adapter *adap) wait_for_completion(&adap->dev_released); /* free bus id */ + mutex_lock(&core_lock); idr_remove(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); @@ -627,9 +637,7 @@ int i2c_del_adapter(struct i2c_adapter *adap) added again */ memset(&adap->dev, 0, sizeof(adap->dev)); - out_unlock: - mutex_unlock(&core_lock); - return res; + return 0; } EXPORT_SYMBOL(i2c_del_adapter); @@ -674,16 +682,15 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) if (res) return res; - mutex_lock(&core_lock); - pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); INIT_LIST_HEAD(&driver->clients); /* Walk the adapters that are already present */ + mutex_lock(&core_lock); class_for_each_device(&i2c_adapter_class, NULL, driver, __attach_adapter); - mutex_unlock(&core_lock); + return 0; } EXPORT_SYMBOL(i2c_register_driver); @@ -721,14 +728,12 @@ static int __detach_adapter(struct device *dev, void *data) void i2c_del_driver(struct i2c_driver *driver) { mutex_lock(&core_lock); - class_for_each_device(&i2c_adapter_class, NULL, driver, __detach_adapter); + mutex_unlock(&core_lock); driver_unregister(&driver->driver); pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); - - mutex_unlock(&core_lock); } EXPORT_SYMBOL(i2c_del_driver); |