ipc4: base_fw: Return an empty list for inactive cores

The behavior expected by the driver on the host is that if the IPC
`IPC4_SCHEDULERS_INFO_GET` is sent for an inactive core, the FW will
return success with an empty list in the payload.

This patch addresses these shortcomings in the implementation by adding
the appropriate IF statement and initializing an empty list regardless
of whether something will be added to it later.

Signed-off-by: Tomasz Leman <[email protected]>

src/audio/base_fw.c

@@ -340,21 +340,23 @@ int schedulers_info_get(uint32_t *data_off_size,
 	if (core_id >= CONFIG_CORE_COUNT)
 		return IPC4_ERROR_INVALID_PARAM;
 
-	if (!cpu_is_me(core_id))
-		return ipc4_process_on_core(core_id, false);
-
 	struct scheduler_props *scheduler_props;
 	/* the internal structs have irregular sizes so we cannot use indexing, and have to
 	 *  reassign pointers for each element
 	 */
 	struct schedulers_info *schedulers_info = (struct schedulers_info *)data;
 
 	schedulers_info->scheduler_count = 0;
-
 	/* smallest response possible is just zero schedulers count
 	 * here we replace max_len from data_off_size to serve as output size
 	 */
 	*data_off_size = sizeof(struct schedulers_info);
+	/* return empty scheduler_props if core is not active */
+	if (!cpu_is_core_enabled(core_id))
+		return IPC4_SUCCESS;
+
+	if (!cpu_is_me(core_id))
+		return ipc4_process_on_core(core_id, false);
 
 	/* ===================== LL_TIMER SCHEDULER INFO ============================ */
 	schedulers_info->scheduler_count++;