diff --git a/drivers/char/hw_random/optee-rng.c b/drivers/char/hw_random/optee-rng.c
index 5bc4700c4dae..a99d82949981 100644
--- a/drivers/char/hw_random/optee-rng.c
+++ b/drivers/char/hw_random/optee-rng.c
@@ -122,14 +122,14 @@ static int optee_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
 	if (max > MAX_ENTROPY_REQ_SZ)
 		max = MAX_ENTROPY_REQ_SZ;
 
-	while (read == 0) {
+	while (read < max) {
 		rng_size = get_optee_rng_data(pvt_data, data, (max - read));
 
 		data += rng_size;
 		read += rng_size;
 
 		if (wait && pvt_data->data_rate) {
-			if (timeout-- == 0)
+			if ((timeout-- == 0) || (read == max))
 				return read;
 			msleep((1000 * (max - read)) / pvt_data->data_rate);
 		} else {