Merge tag 'v3.6-rc7' into next

Linux 3.6-rc7

Requested by David Howells so he can merge his key susbsystem work into
my tree with requisite -linus changesets.

1 files changed, 20 insertions, 2 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 2efa56c5ff2..2091ae8f539 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -637,6 +637,22 @@ static void i2c_adapter_dev_release(struct device *dev)
 }
 
 /*
+ * This function is only needed for mutex_lock_nested, so it is never
+ * called unless locking correctness checking is enabled. Thus we
+ * make it inline to avoid a compiler warning. That's what gcc ends up
+ * doing anyway.
+ */
+static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
+{
+	unsigned int depth = 0;
+
+	while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
+		depth++;
+
+	return depth;
+}
+
+/*
  * Let users instantiate I2C devices through sysfs. This can be used when
  * platform initialization code doesn't contain the proper data for
  * whatever reason. Also useful for drivers that do device detection and
@@ -726,7 +742,8 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
 
 	/* Make sure the device was added through sysfs */
 	res = -ENOENT;
-	mutex_lock(&adap->userspace_clients_lock);
+	mutex_lock_nested(&adap->userspace_clients_lock,
+			  i2c_adapter_depth(adap));
 	list_for_each_entry_safe(client, next, &adap->userspace_clients,
 				 detected) {
 		if (client->addr == addr) {
@@ -1073,7 +1090,8 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 		return res;
 
 	/* Remove devices instantiated from sysfs */
-	mutex_lock(&adap->userspace_clients_lock);
+	mutex_lock_nested(&adap->userspace_clients_lock,
+			  i2c_adapter_depth(adap));
 	list_for_each_entry_safe(client, next, &adap->userspace_clients,
 				 detected) {
 		dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,