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Commit 6ea23039 authored by Jiri Kosina's avatar Jiri Kosina Committed by Jean Delvare
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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: default avatarJiri Kosina <jikos@jikos.cz>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent ad04d5c3

drivers/i2c/i2c-core.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

include/linux/i2c.h

+1 −0
Original line number Diff line number Diff line
@@ -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;