 By winter 588, the Sui attack was in full operation, with three major prongs commanded by Emperor Wen's sons, Yang Guang (later Emperor Yang of Sui) and Yang Jun, and Yang Su, and with Yang Guang in overall command of the operation, assisted by Gao Jiong.Reports from the upper Yangtze, however, were being suppressed by Shi Wenqing and Shen Keqing () and never reached Chen Shubao, as Shi, not realizing the seriousness of the Sui threat, did not want anything to interfere with his own plans to become the governor of Xiang Province (湘州, roughly modern Changsha, Hunan).Yang Su, who attacked from the upper Yangtze, therefore faced no serious opposition and soon controlled the upper Yangtze, not allowing any Chen forces which might have wanted to head downstream to aid the capital to be able to get through.