Commercial banks and their holding companies reported a combined $3.22 billion in income on their mortgage banking operations during the second quarter, the weakest performance for the industry since the depth of the financial crisis in late 2008. Mortgage banking income fell 23.7 percent from the first quarter of 2011, according to a new analysis of bank call-report data by Inside Mortgage Trends. The story is less clear on the production side of the business because of the mammoth loss reported by Bank of America. Through the first six months of the year a troubling period of declining loan production levels and persistent buyback pressure from... [Includes one data chart]