Generally speaking if there is sufficient oil to cover the oil strainer/pickup in the sump while the entire engine's oil channels are filled with oil will be enough to run the engine for a very short time.
Though this will not be good in the long run.
Low oil levels will cause issues with clutch as it's supposed to be covered continually in oil and with the stator.
Usually when conducting a service and refilling the oil, I will refill to the top mark, run the engine for a minute. Allow the engine to sit for approx. 2 mins, then check the oil level again. Normally a small top up to the full mark is required.
Note that the bike should be held upright, centre stand will skew the reading - the best way is to have someone straddle the seat without putting weight on the seat - not that easy to do for most people with average leg length on a tall bike.
Castrol website states: Capacity 2,6 litre (Service fill), Capacity 3 litre (Dry fill), Filter capacity 0,2 litre
With 2.2ltrs in there I can't see there being an issue for being run for such a short time.
Oil at the very bottom edge of the sight window, still means there is oil in there, but not within the recommended range.