misc: mpfs_syscontroller: add mailbox RX helper for service responses

The MPFS system controller run_service() helper only submits the mailbox
request but does not read back the response data. However, the caller
must explicitly receive the response.

Add a public system controller helper to receive mailbox service
responses to populate the response buffer after issuing a system
controller request.

Without this, the drivers copy uninitialised stack data instead of
mailbox response data, resulting in deterministic output.

Signed-off-by: Jamie Gibbons <[email protected]>
Acked-by: Conor Dooley <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/mpfs-mailbox.h b/include/mpfs-mailbox.h
index c0ff327a4ce..39c998e4c8d 100644
--- a/include/mpfs-mailbox.h
+++ b/include/mpfs-mailbox.h
@@ -58,6 +58,8 @@ struct mpfs_sys_serv {
 };
 
 int mpfs_syscontroller_run_service(struct mpfs_syscontroller_priv *sys_controller, struct mpfs_mss_msg *msg);
+int mpfs_syscontroller_recv_response(struct mpfs_syscontroller_priv
+	*sys_controller, struct mpfs_mss_msg *msg, unsigned long timeout_ms);
 int mpfs_syscontroller_read_sernum(struct mpfs_sys_serv *sys_serv_priv, u8 *device_serial_number);
 void mpfs_syscontroller_process_dtbo(struct mpfs_sys_serv *sys_serv_priv);
 struct mpfs_syscontroller_priv *mpfs_syscontroller_get(struct udevice *dev);