Orchestrate recursive quicksort calls via WaitGroup

I am trying to run recursive quicksort calls in parallel:

func quicksort(a []int) {
	quicksortRecursive(a)
	wg.Wait()
	insertionsort(a)
}
func quicksortRecursive(a []int) {
	if len(a) > THRESHOLD {
		l, r := partition(a)
		wg.Add(2)
		go func() {
			quicksortRecursive(a[:r+1])
			wg.Done()
		}()
		go func() {
			go quicksortRecursive(a[l:])
			wg.Done()
		}()
	}
}

The go calls appear overly clunky to me. Is the following, more readable version still correct?

func quicksort(a []int) {
	wg.Add(1)
	quicksortRecursive(a)
	wg.Wait()
	insertionsort(a)
}
func quicksortRecursive(a []int) {
	if len(a) > THRESHOLD {
		l, r := partition(a)
		wg.Add(2)
		go quicksortRecursive(a[:r+1])
		go quicksortRecursive(a[l:])
	}
	wg.Done()
}

I am specifically wondering whether calling the initial wg.Add(1) and the corresponding wg.Done() in the same thread is kosher.

If it works correctly, then it's correct. In terms of code quality, I don't see anything wrong with the approach, other than a slight concern about the use of a global variable for the WaitGroup. If it's a small app it's probably fine, otherwise I would use a local variable created in quicksort and passed as a parameter to quicksortRecursive.