i2c: export i2c_adapter_depth()

For crazy setups in which an i2c gpio expander is behind an i2c gpio
multiplexer controlled by a gpio provided a second expander using the
same device driver we need to explicitly tell lockdep how to handle
nested locking.

Export i2c_adapter_depth() as public API to be reused outside of i2c
core code.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 2 insertions, 7 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index cdbbd9bdb7b4..981de21ab814 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1426,13 +1426,7 @@ static void i2c_adapter_dev_release(struct device *dev)
         complete(&adap->dev_released);
 }
 
-/*
- * 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 i2c_adapter_depth(struct i2c_adapter *adapter)
 {
         unsigned int depth = 0;
 
@@ -1441,6 +1435,7 @@ static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
 
         return depth;
 }
+EXPORT_SYMBOL_GPL(i2c_adapter_depth);
 
 /*
  * Let users instantiate I2C devices through sysfs. This can be used when