staging: vchiq_core: introduce handle_poll

The function slot_handler_func() has very deep indentations. Moving the
poll handling into separate function could improve the readability.
Use the return value to keep the poll_needed handling at the same place.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1622735405-9980-17-git-send-email-stefan.wahren@i2se.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -1992,31 +1992,19 @@ parse_rx_slots(struct vchiq_state *state)
 	}
 }
 
-/* Called by the slot handler thread */
+/**
+ * handle_poll() - handle service polling and other rare conditions
+ * @state:  vchiq state struct
+ *
+ * Context: Process context
+ *
+ * Return:
+ * * 0        - poll handled successful
+ * * -EAGAIN  - retry later
+ */
 static int
-slot_handler_func(void *v)
+handle_poll(struct vchiq_state *state)
 {
-	struct vchiq_state *state = v;
-	struct vchiq_shared_state *local = state->local;
-
-	DEBUG_INITIALISE(local)
-
-	while (1) {
-		DEBUG_COUNT(SLOT_HANDLER_COUNT);
-		DEBUG_TRACE(SLOT_HANDLER_LINE);
-		remote_event_wait(&state->trigger_event, &local->trigger);
-
-		rmb();
-
-		DEBUG_TRACE(SLOT_HANDLER_LINE);
-		if (state->poll_needed) {
-
-			state->poll_needed = 0;
-
-			/*
-			 * Handle service polling and other rare conditions here
-			 * out of the mainline code
-			 */
 	switch (state->conn_state) {
 	case VCHIQ_CONNSTATE_CONNECTED:
 		/* Poll the services as requested */
@@ -2024,24 +2012,19 @@ slot_handler_func(void *v)
 		break;
 
 	case VCHIQ_CONNSTATE_PAUSING:
-				if (queue_message(state, NULL, MAKE_PAUSE,
-					NULL, NULL, 0,
-					QMFLAGS_NO_MUTEX_UNLOCK)
-				    != VCHIQ_RETRY) {
-					vchiq_set_conn_state(state,
-						VCHIQ_CONNSTATE_PAUSE_SENT);
+		if (queue_message(state, NULL, MAKE_PAUSE, NULL, NULL, 0,
+				  QMFLAGS_NO_MUTEX_UNLOCK) != VCHIQ_RETRY) {
+			vchiq_set_conn_state(state, VCHIQ_CONNSTATE_PAUSE_SENT);
 		} else {
 			/* Retry later */
-					state->poll_needed = 1;
+			return -EAGAIN;
 		}
 		break;
 
 	case VCHIQ_CONNSTATE_RESUMING:
-				if (queue_message(state, NULL, MAKE_RESUME,
-					NULL, NULL, 0, QMFLAGS_NO_MUTEX_LOCK)
-					!= VCHIQ_RETRY) {
-					vchiq_set_conn_state(state,
-						VCHIQ_CONNSTATE_CONNECTED);
+		if (queue_message(state, NULL, MAKE_RESUME, NULL, NULL, 0,
+				  QMFLAGS_NO_MUTEX_LOCK) != VCHIQ_RETRY) {
+			vchiq_set_conn_state(state, VCHIQ_CONNSTATE_CONNECTED);
 		} else {
 			/*
 			 * This should really be impossible,
@@ -2056,6 +2039,35 @@ slot_handler_func(void *v)
 		break;
 	}
 
+	return 0;
+}
+
+/* Called by the slot handler thread */
+static int
+slot_handler_func(void *v)
+{
+	struct vchiq_state *state = v;
+	struct vchiq_shared_state *local = state->local;
+
+	DEBUG_INITIALISE(local)
+
+	while (1) {
+		DEBUG_COUNT(SLOT_HANDLER_COUNT);
+		DEBUG_TRACE(SLOT_HANDLER_LINE);
+		remote_event_wait(&state->trigger_event, &local->trigger);
+
+		rmb();
+
+		DEBUG_TRACE(SLOT_HANDLER_LINE);
+		if (state->poll_needed) {
+			state->poll_needed = 0;
+
+			/*
+			 * Handle service polling and other rare conditions here
+			 * out of the mainline code
+			 */
+			if (handle_poll(state) == -EAGAIN)
+				state->poll_needed = 1;
 		}
 
 		DEBUG_TRACE(SLOT_HANDLER_LINE);