php - How to use FOUND_ROWS() on multiple tables -

i have following query executes without error, not return correct number of rows. same query works when selecting 1 table, not two:

select found_rows() `total`  `products` t1  right join `homepage` t2 on `t2`.id = `t1`.id; 

to row count this:

select count(*) `total`  `products` t1  right join `homepage` t2  on `t2`.id = `t1`.id;