search

hexdump0815 / u-boot-misc

notes on building, preparing and installing u-boot for allwinner, rockchip, amlogic, exynos arm socs ...
50 stars 17 forks source link

DRAM and CPU clocks for Allwinner H616 in OrangePiZero2 #4

Open FerGT50 opened 3 years ago

FerGT50 commented 3 years ago

Hello! First of all thanks for your great work. As you know I already managed to fit your kernel (5.11.0rc1-stb616) within my Armbian nightly for OrangePiZero2, and now USB works. :)

Now I'd like to address another issue: the board is quite slow; noticeably slower than with Armbian nightly kernel (5.11.11-sunxi64). With the legacy OrangePi kernel, the CPU runs at 1512000000 Hz and the DRAM at 720000000 Hz; moreover, microSD does 45 MB/s. I think with your kernel, clocks are lower by about 30% (and microSD can't past 22-23 MB/s).

jernej hinted about modifying clocks in u-boot, but honestly I don't know which files I should edit within the source tree: do you have a suggestion? Thank you very much

hexdump0815 commented 3 years ago

i think you have now reached what is currently possible and for everything else patience is required until one of the capable developers continues to work on the remaining topics like dvfs, thermal management and better hdmi support. the h616 is not really well supported yet, so its maybe not the right platform to expect too much from right now.

you can use the orangepi bsp kernel meanwhile, but it is full of ugly hacks, is not being updated with security fixes etc., so not really a good idea. here are my experiments around that kernel and u-boot: https://github.com/hexdump0815/linux-allwinner-h616-kernel and https://github.com/hexdump0815/u-boot-misc/blob/master/readme.h616-legacy

best wishes and good luck - hexdump