From ce24ca965e0014930ca424c28e21a3531b28c141 Mon Sep 17 00:00:00 2001
From: Seungha Yang <seungha@centricular.com>
Date: Tue, 8 Mar 2022 22:38:55 +0900
Subject: [PATCH] transcriberbin: Fix deadlock

Fix race between latency query handler and setup_transcription()
method.

Locking order of setup_transcription() is
state lock -> setup_transcription() -> settings lock
So taking state lock inside of setting lock in src_query()
can cause deadlock.
---
 video/closedcaption/src/transcriberbin/imp.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/video/closedcaption/src/transcriberbin/imp.rs b/video/closedcaption/src/transcriberbin/imp.rs
index 34056002..176238ff 100644
--- a/video/closedcaption/src/transcriberbin/imp.rs
+++ b/video/closedcaption/src/transcriberbin/imp.rs
@@ -396,7 +396,6 @@ impl TranscriberBin {
 
                 if ret {
                     let (_, mut min, _) = upstream_query.result();
-                    let settings = self.settings.lock().unwrap();
                     let received_framerate = {
                         let state = self.state.lock().unwrap();
                         if let Some(state) = state.as_ref() {
@@ -406,6 +405,7 @@ impl TranscriberBin {
                         }
                     };
 
+                    let settings = self.settings.lock().unwrap();
                     if settings.passthrough || !received_framerate {
                         min += settings.latency + settings.accumulate_time;
                     } else if settings.mode.is_rollup() {