Scroll to top in RecyclerView with LinearLayoutManager

Continuing from above comments, ideally, replacing

mRecyclerView.smoothScrollToPosition(0);

in the onClick of the floating action button with

mLayoutManager.scrollToPositionWithOffset(0, 0);

should work. You can also remove the SnackBar code, because you don't need it anyways. So, all in all your above method should look like

public void setFloatingActionButton(final View view) {
    float actionButton = (android.support.design.widget.FloatingActionButton) getActivity()
            .findViewById(R.id.float);
    actionButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView
                    .getLayoutManager();
            layoutManager.scrollToPositionWithOffset(0, 0);
        }
    });
}

And if you say that the above doesnt work, then test if the onClick() is even being called or not. Try adding a log message in it and see if its printed.

Using the method smoothScrollToPosition() worked for me with the newest Android version.

layoutManager.smoothScrollToPosition(mRecyclerView, null, 0);