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authorJiri Kosina <jikos@jikos.cz>2006-12-10 21:21:30 +0100
committerJean Delvare <khali@arrakis.delvare>2006-12-10 21:21:30 +0100
commit6ea23039cb1cc7c379eb5fba0ed2c53291e9bea7 (patch)
treec22887d242a0c3813789c63c4db2fd59b1f3ef7e
parentad04d5c3879dcf79ba0fa1826eab991f7b7a2de8 (diff)
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>
-rw-r--r--drivers/i2c/i2c-core.c2
-rw-r--r--include/linux/i2c.h1
2 files changed, 2 insertions, 1 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 7ca81f42d14..79eaa12474d 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -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);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 9b5d04768c2..08df4169b41 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -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;