UNLIKE AGN FEEDBACK IN GALAXY CLUSTERS IN WHICH HEATING AND COOLING ARE BALANCED AT EACH RADIUS FEED- BACK IN EARLY-TYPE GALAXIES IS OFTEN OVERPOWERED AND ABLE IN PRINCIPLE TO HEAT THE GALAXY QUICKLY. HOW TO SUSTAIN LONG-LIVED UBIQUITOUS JETS IN SUCH SYSTEMS REMAINS A PUZZLE. IF A RESERVOIR OF RELATIVELY QUIESCENT HOT GAS WERE MAINTAINED IN THE VICINITY OF BLACK HOLE HOWEVER IT MAY CONTINUE TO POWER ACCRETION LEADING TO CONTINUOUS ENERGY RELEASE FROM THE BLACK HOLE. RGS ANALYSIS OF A SAMPLE OF ELLIPTICAL GALAXIES SHOWED INDICATIONS OF SUCH FEEDBACK IN M84. WE PROPOSE A DEEP 380 KS OBSERVATION OF THIS SYSTEM WITH THE XMM-NEWTON/RGS TO PROBE THE DYNAMICAL STATE OF THE GAS IN THE INNER FEW KPC AND DETERMINE WHETHER IT IS LARGELY QUIESCENT (IN CONTRAST TO THE ACTIVE GALAXY OUTSKIRTS) AND IS INDEED IN HEATING-COOLING IMBALANCE.