Staging driver fixes for 6.16-rc6

Here are some small driver fixes for the vchiq_arm staging driver:
   - reverts of previous changes that turned out to caused problems.
   - change to prevent a research leak
 
 All of these have been in linux-next this week with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver fixes from Greg KH:
 "Here are some small driver fixes for the vchiq_arm staging driver:

   - reverts of previous changes that turned out to caused problems.

   - change to prevent a resource leak

  All of these have been in linux-next this week with no reported
  problems"

* tag 'staging-6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: vchiq_arm: Make vchiq_shutdown never fail
  Revert "staging: vchiq_arm: Create keep-alive thread during probe"
  Revert "staging: vchiq_arm: Improve initial VCHIQ connect"

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -97,6 +97,13 @@ struct vchiq_arm_state {
 	 * tracked separately with the state.
 	 */
 	int peer_use_count;
+
+	/*
+	 * Flag to indicate that the first vchiq connect has made it through.
+	 * This means that both sides should be fully ready, and we should
+	 * be able to suspend after this point.
+	 */
+	int first_connect;
 };
 
 static int
@@ -273,6 +280,29 @@ static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state
 	return 0;
 }
 
+int
+vchiq_platform_init_state(struct vchiq_state *state)
+{
+	struct vchiq_arm_state *platform_state;
+
+	platform_state = devm_kzalloc(state->dev, sizeof(*platform_state), GFP_KERNEL);
+	if (!platform_state)
+		return -ENOMEM;
+
+	rwlock_init(&platform_state->susp_res_lock);
+
+	init_completion(&platform_state->ka_evt);
+	atomic_set(&platform_state->ka_use_count, 0);
+	atomic_set(&platform_state->ka_use_ack_count, 0);
+	atomic_set(&platform_state->ka_release_count, 0);
+
+	platform_state->state = state;
+
+	state->platform_state = (struct opaque_platform_state *)platform_state;
+
+	return 0;
+}
+
 static struct vchiq_arm_state *vchiq_platform_get_arm_state(struct vchiq_state *state)
 {
 	return (struct vchiq_arm_state *)state->platform_state;
@@ -363,8 +393,7 @@ int vchiq_shutdown(struct vchiq_instance *instance)
 	struct vchiq_state *state = instance->state;
 	int ret = 0;
 
-	if (mutex_lock_killable(&state->mutex))
-		return -EAGAIN;
+	mutex_lock(&state->mutex);
 
 	/* Remove all services */
 	vchiq_shutdown_internal(state, instance);
@@ -981,39 +1010,6 @@ vchiq_keepalive_thread_func(void *v)
 	return 0;
 }
 
-int
-vchiq_platform_init_state(struct vchiq_state *state)
-{
-	struct vchiq_arm_state *platform_state;
-	char threadname[16];
-
-	platform_state = devm_kzalloc(state->dev, sizeof(*platform_state), GFP_KERNEL);
-	if (!platform_state)
-		return -ENOMEM;
-
-	snprintf(threadname, sizeof(threadname), "vchiq-keep/%d",
-		 state->id);
-	platform_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func,
-						   (void *)state, threadname);
-	if (IS_ERR(platform_state->ka_thread)) {
-		dev_err(state->dev, "couldn't create thread %s\n", threadname);
-		return PTR_ERR(platform_state->ka_thread);
-	}
-
-	rwlock_init(&platform_state->susp_res_lock);
-
-	init_completion(&platform_state->ka_evt);
-	atomic_set(&platform_state->ka_use_count, 0);
-	atomic_set(&platform_state->ka_use_ack_count, 0);
-	atomic_set(&platform_state->ka_release_count, 0);
-
-	platform_state->state = state;
-
-	state->platform_state = (struct opaque_platform_state *)platform_state;
-
-	return 0;
-}
-
 int
 vchiq_use_internal(struct vchiq_state *state, struct vchiq_service *service,
 		   enum USE_TYPE_E use_type)
@@ -1329,19 +1325,37 @@ vchiq_check_service(struct vchiq_service *service)
 	return ret;
 }
 
-void vchiq_platform_connected(struct vchiq_state *state)
-{
-	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
-
-	wake_up_process(arm_state->ka_thread);
-}
-
 void vchiq_platform_conn_state_changed(struct vchiq_state *state,
 				       enum vchiq_connstate oldstate,
 				       enum vchiq_connstate newstate)
 {
+	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
+	char threadname[16];
+
 	dev_dbg(state->dev, "suspend: %d: %s->%s\n",
 		state->id, get_conn_state_name(oldstate), get_conn_state_name(newstate));
+	if (state->conn_state != VCHIQ_CONNSTATE_CONNECTED)
+		return;
+
+	write_lock_bh(&arm_state->susp_res_lock);
+	if (arm_state->first_connect) {
+		write_unlock_bh(&arm_state->susp_res_lock);
+		return;
+	}
+
+	arm_state->first_connect = 1;
+	write_unlock_bh(&arm_state->susp_res_lock);
+	snprintf(threadname, sizeof(threadname), "vchiq-keep/%d",
+		 state->id);
+	arm_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func,
+					      (void *)state,
+					      threadname);
+	if (IS_ERR(arm_state->ka_thread)) {
+		dev_err(state->dev, "suspend: Couldn't create thread %s\n",
+			threadname);
+	} else {
+		wake_up_process(arm_state->ka_thread);
+	}
 }
 
 static const struct of_device_id vchiq_of_match[] = {

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c

@@ -3343,7 +3343,6 @@ vchiq_connect_internal(struct vchiq_state *state, struct vchiq_instance *instanc
 			return -EAGAIN;
 
 		vchiq_set_conn_state(state, VCHIQ_CONNSTATE_CONNECTED);
-		vchiq_platform_connected(state);
 		complete(&state->connect);
 	}
 

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h

@@ -575,8 +575,6 @@ int vchiq_send_remote_use(struct vchiq_state *state);
 
 int vchiq_send_remote_use_active(struct vchiq_state *state);
 
-void vchiq_platform_connected(struct vchiq_state *state);
-
 void vchiq_platform_conn_state_changed(struct vchiq_state *state,
 				       enum vchiq_connstate oldstate,
 				  enum vchiq_connstate newstate);