disp: msm: dp: destroy audio workqueue outside session_lock

Change moves destroying dp audio workqueue outside dp session_lock.
As part of disconnect, USB driver uses atomic notifier which holds
rcu_read_lock and calls into DP disconnect callback which needs
session_lock. If another DP threads holds DP session_lock then
we block RCU operations.

Change-Id: I5d565ca149a3a34ebd5ede4fb662982d87454f16
Signed-off-by: Vara Reddy <[email protected]>

msm/dp/dp_display.c

@@ -3347,6 +3347,7 @@ static int dp_display_mst_connector_uninstall(struct dp_display *dp_display,
 	struct sde_connector *sde_conn;
 	struct dp_panel *dp_panel;
 	struct dp_display_private *dp;
+	struct dp_audio *audio = NULL;
 
 	if (!dp_display || !connector) {
 		DP_ERR("invalid input\n");
@@ -3372,13 +3373,17 @@ static int dp_display_mst_connector_uninstall(struct dp_display *dp_display,
 	}
 
 	dp_panel = sde_conn->drv_panel;
-	dp_audio_put(dp_panel->audio);
+
+	/* Make a copy of audio structure to call into dp_audio_put later */
+	audio = dp_panel->audio;
 	dp_panel_put(dp_panel);
 
 	DP_MST_DEBUG("dp mst connector uninstalled. conn:%d\n",
 			connector->base.id);
 
 	mutex_unlock(&dp->session_lock);
+
+	dp_audio_put(audio);
 	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT, dp->state);
 
 	return rc;