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authorAl Viro <viro@zeniv.linux.org.uk>2012-09-26 21:07:20 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-09-26 21:07:20 -0400
commit5905db5ca0ac9a6d5bfe87f86b87cd1bdec3755a (patch)
tree6edb13ed37d842ef0b70d072b94e4c78010f90cf /drivers/i2c/i2c-core.c
parentc5aa1e554a20fb3542c62688ae46049c9225a965 (diff)
parent6f0f9b6b3fcfe5e156f20d4f804f0d505c750b3c (diff)
Merge remote branch 'origin' into for-next
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r--drivers/i2c/i2c-core.c22
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,