I am getting max category post count = 10, every time

Question

I have some categories and each category have some subcategories.

For example :

Entertainment(slug = 'entertainment')
--- Movies
--- Drama
--- Sports

I want to retrieve the number count of all posts in entertainment and its sub categories

But max count i am getting is 10 everytime.When there is total 13 posts its 10 but if less than 10 posts its exact number. it return 8 for 8..but 10 for 13

My code is

function PrinzPostCatCount( $slug ){
    // category posts count
    $args = array(
        'posts_per_page'    => -1,
        'category_name'     => $slug, 
    );
    $post = new WP_Query( $args );
    return (int) $post->post_count;
}

Answer 1

Try to pass 'posts_per_page'=>-1 with the query.

ie

$post = new WP_Query( array('category_name' => $slug, 'posts_per_page'=>-1) );