0001-vcilcs-Avoid-a-potential-deadlock-when-very-threaded.patch

From be3a54cb721546a7b1edf47f338c517fd2a904c3 Mon Sep 17 00:00:00 2001
From: Phil Elwell <[email protected]>
Date: Wed, 4 Nov 2015 17:37:33 +0000
Subject: [PATCH] vcilcs: Avoid a potential deadlock when very threaded

See: https://github.com/raspberrypi/firmware/issues/449
---
 interface/vmcs_host/vcilcs.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/interface/vmcs_host/vcilcs.c b/interface/vmcs_host/vcilcs.c
index e639592..b394637 100644
--- a/interface/vmcs_host/vcilcs.c
+++ b/interface/vmcs_host/vcilcs.c
@@ -716,14 +716,24 @@ static int ilcs_execute_function_ex(ILCS_SERVICE_T *st, IL
_FUNCTION_T func,
          // we'll pause until we can carry on and hope that's sufficient.
          vcos_mutex_unlock(&st->wait_mtx);

-         vcos_event_wait(&st->wait_event);
-
          // if we're the ilcs thread, then the waiters might need
          // us to handle their response, so try and clear those now
          if(vcos_thread_current() == &st->thread)
-            while(ilcs_process_message(st, 0))
-               if(st->kill_service >= CLOSED_CALLBACK)
-                  return -1;
+         {
+            while (vcos_event_try(&st->wait_event) != VCOS_SUCCESS)
+            {
+               while(ilcs_process_message(st, 0))
+                  if(st->kill_service >= CLOSED_CALLBACK)
+                     return -1;
+               if (vcos_event_try(&st->wait_event) == VCOS_SUCCESS)
+                  break;
+               vcos_sleep(1);
+            }
+         }
+         else
+         {
+            vcos_event_wait(&st->wait_event);
+         }

          vcos_mutex_lock(&st->wait_mtx);
       }
--
1.9.1