diff --git a/sys/dev/firmware/arm/scmi.c b/sys/dev/firmware/arm/scmi.c
--- a/sys/dev/firmware/arm/scmi.c
+++ b/sys/dev/firmware/arm/scmi.c
@@ -85,7 +85,7 @@
 	req->msg_header |= SCMI_MSG_TYPE_CMD << SCMI_HDR_MESSAGE_TYPE_S;
 	req->msg_header |= req->protocol_id << SCMI_HDR_PROTOCOL_ID_S;
 
-	ret = scmi_shmem_prepare_msg(sc->a2p_dev, req);
+	ret = scmi_shmem_prepare_msg(sc->a2p_dev, req, cold);
 	if (ret != 0)
 		return (ret);
 
diff --git a/sys/dev/firmware/arm/scmi_mailbox.c b/sys/dev/firmware/arm/scmi_mailbox.c
--- a/sys/dev/firmware/arm/scmi_mailbox.c
+++ b/sys/dev/firmware/arm/scmi_mailbox.c
@@ -49,6 +49,7 @@
 
 #include "scmi.h"
 #include "scmi_protocols.h"
+#include "scmi_shmem.h"
 
 struct scmi_mailbox_softc {
 	struct scmi_softc	base;
@@ -91,7 +92,7 @@
 
 	do {
 		if (cold) {
-			if (arm_doorbell_get(sc->db))
+			if (scmi_shmem_poll_msg(sc->base.a2p_dev))
 				break;
 			DELAY(10000);
 		} else {
diff --git a/sys/dev/firmware/arm/scmi_shmem.h b/sys/dev/firmware/arm/scmi_shmem.h
--- a/sys/dev/firmware/arm/scmi_shmem.h
+++ b/sys/dev/firmware/arm/scmi_shmem.h
@@ -63,7 +63,9 @@
 struct scmi_req;
 
 device_t	scmi_shmem_get(device_t sdev, phandle_t node, int index);
-int		scmi_shmem_prepare_msg(device_t dev, struct scmi_req *req);
+int		scmi_shmem_prepare_msg(device_t dev, struct scmi_req *req,
+    bool polling);
+bool scmi_shmem_poll_msg(device_t);
 int scmi_shmem_read_msg_header(device_t dev, uint32_t *msg_header);
 int scmi_shmem_read_msg_payload(device_t dev, uint8_t *buf, uint32_t buf_len);
 
diff --git a/sys/dev/firmware/arm/scmi_shmem.c b/sys/dev/firmware/arm/scmi_shmem.c
--- a/sys/dev/firmware/arm/scmi_shmem.c
+++ b/sys/dev/firmware/arm/scmi_shmem.c
@@ -168,7 +168,7 @@
 }
 
 int
-scmi_shmem_prepare_msg(device_t dev, struct scmi_req *req)
+scmi_shmem_prepare_msg(device_t dev, struct scmi_req *req, bool polling)
 {
 	struct scmi_smt_header hdr = {};
 	uint32_t channel_status;
@@ -185,7 +185,10 @@
 	hdr.channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
 	hdr.msg_header = htole32(req->msg_header);
 	hdr.length = htole32(sizeof(req->msg_header) + req->in_size);
-	hdr.flags |= SCMI_SHMEM_FLAG_INTR_ENABLED;
+	if (!polling)
+		hdr.flags |= SCMI_SHMEM_FLAG_INTR_ENABLED;
+	else
+		hdr.flags &= ~SCMI_SHMEM_FLAG_INTR_ENABLED;
 
 	/* Write header */
 	scmi_shmem_write(dev, 0, &hdr, SMT_SIZE_HEADER);
@@ -239,6 +242,17 @@
 	return (0);
 }
 
+bool scmi_shmem_poll_msg(device_t dev)
+{
+	uint32_t status;
+
+	scmi_shmem_read(dev, SMT_OFFSET_CHAN_STATUS, &status,
+	    SMT_SIZE_CHAN_STATUS);
+
+	return (status & (SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR |
+	    SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE));
+}
+
 static device_method_t shmem_methods[] = {
 	DEVMETHOD(device_probe,		shmem_probe),
 	DEVMETHOD(device_attach,	shmem_attach),