Chengdu - Litang by bus

Hello everyone,

I am planning to go to Litang for this year Horse Racing festival. I found some information on how to get there, but most of it is a little bit confusing. Is there someone who could explain the route by bus from Chengdu? Is it one long bus ride or 2 shorter ones with a need of staying overnight in Kangding?

Thanks in advance for your help!