Only write new message to the tx mbox queue if slot is available. If
queue is full, then do not send new mbox notification.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
---
 drivers/remoteproc/xlnx_r5_remoteproc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
index 109831c5815c..46c20b603bc7 100644
--- a/drivers/remoteproc/xlnx_r5_remoteproc.c
+++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
@@ -9,6 +9,7 @@
 #include <linux/firmware/xlnx-zynqmp.h>
 #include <linux/kernel.h>
 #include <linux/mailbox_client.h>
+#include <linux/mailbox_controller.h>
 #include <linux/mailbox/zynqmp-ipi-message.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -341,7 +342,11 @@ static void zynqmp_r5_rproc_kick(struct rproc *rproc, int vqid)
 	int ret;
 
 	ipi = r5_core->ipi;
-	if (!ipi)
+	if (!ipi || !ipi->tx_chan)
+		return;
+
+	/* Do not need new kick as already many kicks are pending. */
+	if (ipi->tx_chan->cl->tx_slots_avail_ro == 0)
 		return;
 
 	mb_msg = (struct zynqmp_ipi_message *)ipi->tx_mc_buf;
-- 
2.34.1