[RFC PATCH 4/4] ASoC: SOF: Intel: hda-dai: fix potential locking issue

[Pierre-Louis Bossart]

The initial hdac_stream code was adapted a third time with the same
locking issues. Move the spin_lock outside the loops and make sure the
fields are protected on read/write.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 sound/soc/sof/intel/hda-dai.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/sound/soc/sof/intel/hda-dai.c b/sound/soc/sof/intel/hda-dai.c
index d71165fb6fad..e349f06c49fa 100644
--- a/sound/soc/sof/intel/hda-dai.c
+++ b/sound/soc/sof/intel/hda-dai.c
@@ -72,6 +72,7 @@ static struct hdac_ext_stream *
 		return NULL;
 	}
 
+	spin_lock_irq(&bus->reg_lock);
 	list_for_each_entry(stream, &bus->stream_list, list) {
 		struct hdac_ext_stream *hstream =
 			stream_to_hdac_ext_stream(stream);
@@ -111,12 +112,12 @@ static struct hdac_ext_stream *
 		 * is updated in snd_hdac_ext_stream_decouple().
 		 */
 		if (!res->decoupled)
-			snd_hdac_ext_stream_decouple(bus, res, true);
-		spin_lock_irq(&bus->reg_lock);
+			snd_hdac_ext_stream_decouple_locked(bus, res, true);
+
 		res->link_locked = 1;
 		res->link_substream = substream;
-		spin_unlock_irq(&bus->reg_lock);
 	}
+	spin_unlock_irq(&bus->reg_lock);
 
 	return res;
 }
-- 
2.25.1