Android Up button not working

The correct way to do it is to override public boolean onNavigateUp() just like overriding onBackPressed().

Here is how you can implement this, try this code

use android.R.id.home instead of R.id.home or R.id.homeAsUp

public boolean onOptionsItemSelected(final MenuItem item) {

        switch (item.getItemId()) {
            case android.R.id.home:
                //use onBackPressed() OR finish();
                return true;

            default:
                return super.onOptionsItemSelected(item);
        }
    }