i2c: mux: pca9541: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)

Locking the root adapter for __i2c_transfer will deadlock if the
device sits behind a mux-locked I2C mux. Switch to the finer-grained
i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
sit behind a mux-locked mux, the two locking variants are equivalent.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/muxes/i2c-mux-pca9541.c b/drivers/i2c/muxes/i2c-mux-pca9541.c
index 6a39adaf433f4ab4979ebd1e7b875cbbf0bbb846..bc7c8cee5a8ce11a188ecf2c78041fcda8419333 100644 (file)
--- a/drivers/i2c/muxes/i2c-mux-pca9541.c
+++ b/drivers/i2c/muxes/i2c-mux-pca9541.c
@@ -345,11 +345,11 @@ static int pca9541_probe(struct i2c_client *client,
 
        /*
         * I2C accesses are unprotected here.
-        * We have to lock the adapter before releasing the bus.
+        * We have to lock the I2C segment before releasing the bus.
         */
-       i2c_lock_adapter(adap);
+       i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
        pca9541_release_bus(client);
-       i2c_unlock_adapter(adap);
+       i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
 
        /* Create mux adapter */