CEDAR RAPIDS — Community advocates are publicly calling on the city to permanently revoke Charles A. Davisson’s permit to lease property in Cedar Rapids, saying he is “not fit to be a landlord” given housing code violations, police calls, shootings and other issues surrounding a Bever Avenue SE property.Residents are circulating a petition they hope will prompt Cedar Rapids officials to “revoke his landlord license permanently” following a report this month in The Gazette that the city Housing Board of Appeals had taken the unusual step of suspending for six months Davisson’s permission to rent out 2307 Bever Ave.