diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c
index 7cc4c30af1a7..65976a3ab591 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/i2c.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/i2c.c
@@ -427,7 +427,7 @@ mlxsw_i2c_cmd(struct device *dev, u16 opcode, u32 in_mod, size_t in_mbox_size,
 	} else {
 		/* No input mailbox is case of initialization query command. */
 		reg_size = MLXSW_I2C_MAX_DATA_SIZE;
-		num = reg_size / mlxsw_i2c->block_size;
+		num = DIV_ROUND_UP(reg_size, mlxsw_i2c->block_size);
 
 		if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) {
 			dev_err(&client->dev, "Could not acquire lock");