save_post && DOING_AUTOSAVE

<?php
// Example 1: Cancel the action if WordPress is doing autosave.
add_action( 'save_post', function( $post_id ){
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) { // WordPress is doing autosave.
        return; // cancel your action
    }

    //...your action here...
} );

// Example 2: Cancel the action if WordPress is doing autosave and that the
// post has been successfully autosaved...
add_action( 'save_post', function( $post_id ){
    if (
        ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) && // WordPress is doing autosave
        wp_is_post_autosave( $post_id )                      // and the autosave succeeded.
    ) {
        return; // cancel your action
    }

    //...your action here...
} );