EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Total 2800
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Landed in Emergency Condition; Flight Crew Diverted
Aircraft
Cruising at FL250 due to limitation of PACK 2 deferred. CA (Captain) noticed smoke in cockpit and we ran smoke in cockpit procedure backed up by checklist. Informed flight attendant and she said no smoke in cabin.  Performed an immediate descent to 3;500 feet as directed by ATC for visual to Runway X at ZZZ. Vehicles escorted us to Gate X. Fire services performed a sweep for hotspots and found none. Deplaned aircraft and a ferry flight was sent to retrieve passengers.Not sure [of cause] at this time. Could have been avionics or a PACK leak.To make it easier for crew to hear each other and ATC; microphone and oxygen masks should be improved to reduce oxygen noise over ICS (Inter Communication System) and reduce workload due to excess noise.
EMB-145 flight crew reported smoke in cockpit during cruise resulting in a diversion.