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]> --- drivers/misc/mpfs_syscontroller.c | 28 ++++++++++++++++++++++++---- include/mpfs-mailbox.h | 1 + 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/misc/mpfs_syscontroller.c b/drivers/misc/mpfs_syscontroller.c index f608d5518b0..61d6780f0b9 100644 --- a/drivers/misc/mpfs_syscontroller.c +++ b/drivers/misc/mpfs_syscontroller.c @@ -85,6 +85,28 @@ int mpfs_syscontroller_run_service(struct mpfs_syscontroller_priv *sys_controlle } EXPORT_SYMBOL_GPL(mpfs_syscontroller_run_service); +/** + * mpfs_syscontroller_recv_response() - Receive the MPFS system service response + * @sys_controller: MPFS system controller instance + * @msg: System service message + * @timeout_ms: Timeout in milliseconds + * + * Receive the mailbox response for a previously issued MPFS system + * controller service request and populate the response buffer. + * + * Return: 0 if all goes good, else appropriate error message. + */ +int mpfs_syscontroller_recv_response(struct mpfs_syscontroller_priv *sys_controller, struct mpfs_mss_msg *msg, unsigned long timeout_ms) +{ + int ret; + + ret = mbox_recv(&sys_controller->chan, msg, timeout_ms); + if (ret) + dev_err(sys_controller->chan.dev, "Service failed: %d, abort. Failure: %u\n", ret, msg->response->resp_status); + return ret; +} +EXPORT_SYMBOL_GPL(mpfs_syscontroller_recv_response); + /** * mpfs_syscontroller_read_sernum() - Use system service to read the device serial number * @sys_serv_priv: system service private data @@ -116,11 +138,9 @@ int mpfs_syscontroller_read_sernum(struct mpfs_sys_serv *sys_serv_priv, u8 *devi } /* Receive the response */ - ret = mbox_recv(&sys_serv_priv->sys_controller->chan, &msg, timeoutsecs); - if (ret) { - dev_err(sys_serv_priv->sys_controller->chan.dev, "Service failed: %d, abort. Failure: %u\n", ret, msg.response->resp_status); + ret = mpfs_syscontroller_recv_response(sys_serv_priv->sys_controller, &msg, timeoutsecs); + if (ret) return ret; - } debug("%s: Read successful %s\n", __func__, sys_serv_priv->sys_controller->chan.dev->name); diff --git a/include/mpfs-mailbox.h b/include/mpfs-mailbox.h index c0ff327a4ce..3922e8d1019 100644 --- a/include/mpfs-mailbox.h +++ b/include/mpfs-mailbox.h @@ -58,6 +58,7 @@ 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); -- 2.43.0
