From 2e7214b6fa5c392eb42d69d0fd39c006a02f030c Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Tue, 13 Oct 2020 23:07:51 -0700
Subject: [PATCH] kern: perform rescheduling on dispatch re-enable (closes
 #1169)

---
 .../include/mesosphere/kern_k_scheduler.hpp   |  4 ++-
 .../include/mesosphere/kern_k_thread.hpp      | 15 +---------
 .../source/kern_k_scoped_disable_dispatch.cpp | 28 +++++++++++++++++++
 3 files changed, 32 insertions(+), 15 deletions(-)
 create mode 100644 libraries/libmesosphere/source/kern_k_scoped_disable_dispatch.cpp

diff --git a/libraries/libmesosphere/include/mesosphere/kern_k_scheduler.hpp b/libraries/libmesosphere/include/mesosphere/kern_k_scheduler.hpp
index b38956fb2..885c1d07e 100644
--- a/libraries/libmesosphere/include/mesosphere/kern_k_scheduler.hpp
+++ b/libraries/libmesosphere/include/mesosphere/kern_k_scheduler.hpp
@@ -48,6 +48,7 @@ namespace ams::kern {
         private:
             friend class KScopedSchedulerLock;
             friend class KScopedSchedulerLockAndSleep;
+            friend class KScopedDisableDispatch;
         private:
             SchedulingState state;
             bool is_active;
@@ -161,8 +162,9 @@ namespace ams::kern {
             }
 
             ALWAYS_INLINE void ScheduleOnInterrupt() {
-                KScopedDisableDispatch dd;
+                GetCurrentThread().DisableDispatch();
                 this->Schedule();
+                GetCurrentThread().EnableDispatch();
             }
 
             void RescheduleOtherCores(u64 cores_needing_scheduling);
diff --git a/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp b/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp
index a7f36f95b..357e8d085 100644
--- a/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp
+++ b/libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp
@@ -559,20 +559,7 @@ namespace ams::kern {
                 GetCurrentThread().DisableDispatch();
             }
 
-            ALWAYS_INLINE ~KScopedDisableDispatch() {
-                GetCurrentThread().EnableDispatch();
-            }
-    };
-
-    class KScopedEnableDispatch {
-        public:
-            explicit ALWAYS_INLINE KScopedEnableDispatch() {
-                GetCurrentThread().EnableDispatch();
-            }
-
-            ALWAYS_INLINE ~KScopedEnableDispatch() {
-                GetCurrentThread().DisableDispatch();
-            }
+            ~KScopedDisableDispatch();
     };
 
     ALWAYS_INLINE KExceptionContext *GetExceptionContext(KThread *thread) {
diff --git a/libraries/libmesosphere/source/kern_k_scoped_disable_dispatch.cpp b/libraries/libmesosphere/source/kern_k_scoped_disable_dispatch.cpp
new file mode 100644
index 000000000..413390577
--- /dev/null
+++ b/libraries/libmesosphere/source/kern_k_scoped_disable_dispatch.cpp
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <mesosphere.hpp>
+
+namespace ams::kern {
+
+    KScopedDisableDispatch::~KScopedDisableDispatch() {
+        if (GetCurrentThread().GetDisableDispatchCount() <= 1) {
+            Kernel::GetScheduler().RescheduleCurrentCore();
+        } else {
+            GetCurrentThread().EnableDispatch();
+        }
+    }
+
+}