[RESEND PATCH] soundwire: add slave device to linked list after device_register()

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

We currently add the slave device to a linked list before
device_register(), and then remove it if device_register() fails.

It's not clear why this sequence was necessary, this patch moves the
linked list management to after the device_register().

Suggested-by: Keyon Jie <yang.jie@xxxxxxxxxxxxxxx>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
 drivers/soundwire/slave.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index 0eed38a79c6d..ff01b96c6e56 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -65,9 +65,6 @@ int sdw_slave_add(struct sdw_bus *bus,
 	for (i = 0; i < SDW_MAX_PORTS; i++)
 		init_completion(&slave->port_ready[i]);
 
-	mutex_lock(&bus->bus_lock);
-	list_add_tail(&slave->node, &bus->slaves);
-	mutex_unlock(&bus->bus_lock);
 
 	ret = device_register(&slave->dev);
 	if (ret) {
@@ -77,13 +74,15 @@ int sdw_slave_add(struct sdw_bus *bus,
 		 * On err, don't free but drop ref as this will be freed
 		 * when release method is invoked.
 		 */
-		mutex_lock(&bus->bus_lock);
-		list_del(&slave->node);
-		mutex_unlock(&bus->bus_lock);
 		put_device(&slave->dev);
 
 		return ret;
 	}
+
+	mutex_lock(&bus->bus_lock);
+	list_add_tail(&slave->node, &bus->slaves);
+	mutex_unlock(&bus->bus_lock);
+
 	sdw_slave_debugfs_init(slave);
 
 	return ret;
-- 
2.17.1