how to sync with mainline

Hi All, I am a freshman to linaro. I found people sent some patches to linaro-dev@lists.linaro.org. Here I have 2 questions: 1. Whether will linaro send those patches based on newest tree to Linus' mainline or not? Or developers need to send those patches to mainline by themselves? Is there any document to describe how linaro contribute patches to mainline? 2. If other SoC companies work based on linaro's linux-linaro-next.git, whether it will not need to work based on Linus' tree since linux-linaro-next.git will sync with mainline? Thanks Barry