7 files changed, 25 insertions, 14 deletions
diff --git a/drivers/mailbox/apple-mbox.c b/drivers/mailbox/apple-mbox.c
index 2ee49734f40..39a7edc0285 100644
--- a/drivers/mailbox/apple-mbox.c
+++ b/drivers/mailbox/apple-mbox.c
@@ -59,7 +59,7 @@ static int apple_mbox_recv(struct mbox_chan *chan, void *data)
 	return 0;
 }
 
-struct mbox_ops apple_mbox_ops = {
+static const struct mbox_ops apple_mbox_ops = {
 	.of_xlate = apple_mbox_of_xlate,
 	.send = apple_mbox_send,
 	.recv = apple_mbox_recv,
diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index c7eaa3de96f..fd0fce21d78 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -387,7 +387,7 @@ int imx_mu_of_xlate(struct mbox_chan *chan, struct ofnode_phandle_args *args)
 	return plat->dcfg->of_xlate(chan, args);
 }
 
-struct mbox_ops imx_mu_ops = {
+static const struct mbox_ops imx_mu_ops = {
 	.of_xlate = imx_mu_of_xlate,
 	.request  = imx_mu_chan_request,
 	.rfree    = imx_mu_chan_free,
diff --git a/drivers/mailbox/k3-sec-proxy.c b/drivers/mailbox/k3-sec-proxy.c
index 6f5ad37919f..6eebfcd3601 100644
--- a/drivers/mailbox/k3-sec-proxy.c
+++ b/drivers/mailbox/k3-sec-proxy.c
@@ -293,7 +293,7 @@ static int k3_sec_proxy_recv(struct mbox_chan *chan, void *data)
 	return 0;
 }
 
-struct mbox_ops k3_sec_proxy_mbox_ops = {
+static const struct mbox_ops k3_sec_proxy_mbox_ops = {
 	.of_xlate = k3_sec_proxy_of_xlate,
 	.request = k3_sec_proxy_request,
 	.rfree = k3_sec_proxy_free,
diff --git a/drivers/mailbox/mpfs-mbox.c b/drivers/mailbox/mpfs-mbox.c
index b1ce377525e..8b7a2719330 100644
--- a/drivers/mailbox/mpfs-mbox.c
+++ b/drivers/mailbox/mpfs-mbox.c
@@ -18,6 +18,7 @@
 #include <linux/compat.h>
 #include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/iopoll.h>
 #include <log.h>
 #include <mailbox-uclass.h>
 #include <mpfs-mailbox.h>
@@ -60,11 +61,15 @@ static int mpfs_mbox_send(struct mbox_chan *chan, const void *data)
 	u32 mailbox_val, cmd_shifted, value;
 	u8 *byte_buf;
 	u8 idx, byte_idx, byte_offset;
+	int ret;
 
 	u32 *word_buf = (u32 *)msg->cmd_data;
 
-	if (mpfs_mbox_busy(chan))
-		return -EBUSY;
+	ret = regmap_read_poll_timeout(mbox->control_scb, SERVICES_SR_OFFSET,
+				       value, !(value & SERVICE_SR_BUSY_MASK),
+				       1, 20);
+	if (ret)
+		return ret;
 
 	for (idx = 0; idx < (msg->cmd_data_size / BYTES_4); idx++)
 		writel(word_buf[idx], mbox->mbox_base + msg->mbox_offset + idx * BYTES_4);
@@ -86,13 +91,19 @@ static int mpfs_mbox_send(struct mbox_chan *chan, const void *data)
 
 	regmap_write(mbox->control_scb, SERVICES_CR_OFFSET, cmd_shifted);
 
-	do {
-		regmap_read(mbox->control_scb, SERVICES_CR_OFFSET, &value);
-	} while (SERVICE_CR_REQ_MASK == (value & SERVICE_CR_REQ_MASK));
+	ret = regmap_read_poll_timeout(mbox->control_scb, SERVICES_CR_OFFSET,
+				       value, !(value & SERVICE_CR_REQ_MASK),
+				       1, /* poll every 1 µs */
+				       20); /* timeout 20 ms */
+	if (ret)
+		return ret;
 
-	do {
-		regmap_read(mbox->control_scb, SERVICES_SR_OFFSET, &value);
-	} while (SERVICE_SR_BUSY_MASK == (value & SERVICE_SR_BUSY_MASK));
+	ret = regmap_read_poll_timeout(mbox->control_scb, SERVICES_SR_OFFSET,
+				       value, !(value & SERVICE_SR_BUSY_MASK),
+				       1,
+				       20);
+	if (ret)
+		return ret;
 
 	msg->response->resp_status = (value >> SERVICE_SR_STATUS_SHIFT);
 	if (msg->response->resp_status)
diff --git a/drivers/mailbox/renesas-mfis.c b/drivers/mailbox/renesas-mfis.c
index 1e9e8285974..19b801e56a6 100644
--- a/drivers/mailbox/renesas-mfis.c
+++ b/drivers/mailbox/renesas-mfis.c
@@ -29,7 +29,7 @@ static int mfis_send(struct mbox_chan *chan, const void *data)
 	return 0;
 }
 
-struct mbox_ops mfis_mbox_ops = {
+static const struct mbox_ops mfis_mbox_ops = {
 	.send		= mfis_send,
 };
 
diff --git a/drivers/mailbox/sandbox-mbox.c b/drivers/mailbox/sandbox-mbox.c
index 87e06e492fe..d6ac758c4d8 100644
--- a/drivers/mailbox/sandbox-mbox.c
+++ b/drivers/mailbox/sandbox-mbox.c
@@ -86,7 +86,7 @@ static const struct udevice_id sandbox_mbox_ids[] = {
 	{ }
 };
 
-struct mbox_ops sandbox_mbox_mbox_ops = {
+static const struct mbox_ops sandbox_mbox_mbox_ops = {
 	.request = sandbox_mbox_request,
 	.rfree = sandbox_mbox_free,
 	.send = sandbox_mbox_send,
diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c
index dda108735fc..49f7795b3cd 100644
--- a/drivers/mailbox/stm32-ipcc.c
+++ b/drivers/mailbox/stm32-ipcc.c
@@ -147,7 +147,7 @@ static const struct udevice_id stm32_ipcc_ids[] = {
 	{ }
 };
 
-struct mbox_ops stm32_ipcc_mbox_ops = {
+static const struct mbox_ops stm32_ipcc_mbox_ops = {
 	.request = stm32_ipcc_request,
 	.rfree = stm32_ipcc_free,
 	.send = stm32_ipcc_send,