Java Stackoverflow Error Recursion

This code I have written works great until a certain input size. If the input gets too large, I get a "java.lang.StackOverflowError". I have read some other entries on stackoverflow regarding this topic and I think I got an error in my recursion- but I can't find it. Here is the code:

public int partition(int[] A, int l, int r, int x){

    int i = l-1;
    int j = r;
    int exchange;

    while(i <= j){
        while(A[i] > x){
            i++;
        }

        while(j >= i && A[j] <= x){
            j--;
        }

        if(i < j){
            exchange = A[i];
            A[i] = A[j];
            A[j] = exchange;
        }
    }

    if(A[i] < A[r]){
        exchange = A[i];
        A[i] = A[r];
        A[r] = exchange;
    }

    return i;
}

public void quicksort(int[] A, int l, int r){
    int pivot = 0;
    int x = 0;

    if(l < r){
        x = A[r];
        pivot = partition(A, l, r, x);
        quicksort(A, l, pivot-1);
        quicksort(A, pivot+1, r);
    }
}