drivers: firmware: scmi: clear rx channel status in rx notification cb

Clear the SCMI shared memory channel status after processing RX
notifications in the mailbox callback for proper P2A flow management.

In SCMI P2A (Platform to Application) flow, the application side
must explicitly clear the channel status after processing incoming
messages from the platform. This is different from A2P (Application
to Platform) TX flow where the cleanup is handled by the peer
(platform) side.

Signed-off-by: Yongxu Wang <[email protected]>

Author: yongxu-wang15

drivers/firmware/scmi/mailbox.c

@@ -27,9 +27,12 @@ static void scmi_mbox_rx_notify_cb(const struct device *mbox,
 				struct mbox_msg *data)
 {
 	struct scmi_channel *scmi_chan = user_data;
+	struct scmi_mbox_channel *mbox_chan = scmi_chan->data;
+	const struct device *shmem = mbox_chan->shmem;
 
 	if (scmi_chan->cb) {
 		scmi_chan->cb(scmi_chan);
+		scmi_shmem_clear_channel_status(shmem);
 	}
 }