i2c: add sanity check to i2c_put_adapter

i2c_put_adapter dereferences i2c_adapter pointer passed without check
for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter
called with NULL and behave the same way i2c_release_client does already.
It allows to simplify drivers where you need to release the adapter
during probe failures.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f32ca293ae0e30674a436afb4bc431cdb743de28..d075df641c2ca19c2c80a62142918eea8246130e 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1825,7 +1825,8 @@ EXPORT_SYMBOL(i2c_get_adapter);
 
 void i2c_put_adapter(struct i2c_adapter *adap)
 {
-       module_put(adap->owner);
+       if (adap)
+               module_put(adap->owner);
 }
 EXPORT_SYMBOL(i2c_put_adapter);