Rockchip RK3399 SOC is very slow

[Victor Krawiec]

Hello U-Boot community,

I recently moved from Rockchip's vendor U-Boot to mainline U-Boot. I noticed that the boot time on RK3399 is very slow compared to the vendor version. It takes around 8 seconds from power up to kernel start while the vendor one takes 2 seconds.

In README.rockchip "Future work" section it is written "Run CPU at full speed (code exists but we only see ~60 DMIPS maximum)" which implies that the current mainline implementation lacks CPU configuration to make it fast.

I'm very interested in a fix for this problem. The vendor Rockchip tree is based on U-Boot 2017 and its getting more and more difficult to use it. 

Therefore I have some questions to start working on this topic:
- Could anyone point me in which part of the code to start digging for a potential fix ? Is it related to the PMIC or another subsystem ?
- Has anyone tried to fix this problem and if yes why was the development abandoned ?

Best regards
Victor