i2c: Add support for nested i2c bus locking

This patch adds the 'level' field into the i2c_adapter structure, which is 
used to represent the 'logical' level of nesting for the purposes of 
lockdep. This field is then used in the i2c_transfer() function, to 
acquire the per-adapter bus_lock with correct nesting level.

Signed-off-by: Jiri Kosina <jikos@jikos.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Jiri Kosina 2006-12-10 21:21:30 +01:00 committed by Jean Delvare
parent ad04d5c387
commit 6ea23039cb
2 changed files with 2 additions and 1 deletions

View file

@ -603,7 +603,7 @@ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
}
#endif
mutex_lock(&adap->bus_lock);
mutex_lock_nested(&adap->bus_lock, adap->level);
ret = adap->algo->master_xfer(adap,msgs,num);
mutex_unlock(&adap->bus_lock);

View file

@ -216,6 +216,7 @@ struct i2c_adapter {
int (*client_unregister)(struct i2c_client *);
/* data fields that are valid for all devices */
u8 level; /* nesting level for lockdep */
struct mutex bus_lock;
struct mutex clist_lock;