China Visa 240 hours Itinerary

Hello All,

Looked at various resources online but seem to get mixed answers. Traveling to China next month in the following order:

Japan -> Shanghai -> Chongqing -> Hong Kong -> Los Angeles

From what I’ve read, no Visa is required for US citizen with this route (less than 10 days in China) but just want to make sure in order to avoid any trouble at customs.

Appreciate any information and confirmation!