[PATCH 4.18 01/53] soundwire: Fix duplicate stream state assignment

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shreyas NC <shreyas.nc@xxxxxxxxx>

[ Upstream commit 0aebe40bae6cf5652fdc3d05ecee15fbf5748194 ]

For a SoundWire stream it is expected that a Slave is added to the
stream before Master is added.

So, move the stream state to CONFIGURED after the first Slave is
added and remove the stream state assignment for Master add.
Along with these changes, add additional comments to explain the same.

Signed-off-by: Shreyas NC <shreyas.nc@xxxxxxxxx>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/soundwire/stream.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -1123,8 +1123,6 @@ int sdw_stream_add_master(struct sdw_bus
 	if (ret)
 		goto stream_error;
 
-	stream->state = SDW_STREAM_CONFIGURED;
-
 stream_error:
 	sdw_release_master_stream(stream);
 error:
@@ -1141,6 +1139,10 @@ EXPORT_SYMBOL(sdw_stream_add_master);
  * @stream: SoundWire stream
  * @port_config: Port configuration for audio stream
  * @num_ports: Number of ports
+ *
+ * It is expected that Slave is added before adding Master
+ * to the Stream.
+ *
  */
 int sdw_stream_add_slave(struct sdw_slave *slave,
 		struct sdw_stream_config *stream_config,
@@ -1186,6 +1188,12 @@ int sdw_stream_add_slave(struct sdw_slav
 	if (ret)
 		goto stream_error;
 
+	/*
+	 * Change stream state to CONFIGURED on first Slave add.
+	 * Bus is not aware of number of Slave(s) in a stream at this
+	 * point so cannot depend on all Slave(s) to be added in order to
+	 * change stream state to CONFIGURED.
+	 */
 	stream->state = SDW_STREAM_CONFIGURED;
 	goto error;