i2c: Use a separate mutex for userspace client lists

Moving userspace-instantiated clients to separate lists wasn't nearly
enough to avoid deadlocks in multiplexed bus cases. We also want to
have a dedicated mutex to protect each list.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 5bf0f4beea31..798bad8741e4 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -368,6 +368,7 @@ struct i2c_adapter {
         char name[48];
         struct completion dev_released;
 
+        struct mutex userspace_clients_lock;
         struct list_head userspace_clients;
 };
 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)