Personal suggestion: Armbian Kernel integration for RK3399 boot time optimization (DHO80X series, might be relevant for other oscilloscopes)

[szoltysek]

Hello 👋🏻

I was looking at your TODO list and your goal to transition the kernel from 4.4.179 to 5.10.209 to shave down boot times caught my eye. Since you're launching Debian/Debian-based distro on these oscilloscopes, wouldn't utilization of Armbian's kernel 6.18.20 / 6.18.22 (which is much more fresh than 5.10.209) be easier?

These oscilloscopes don't require many quirks and tweaks since they utilize widely maintained Rockchip CPU/GPUs.
From my experience - testing a pre-compiled Armbian kernel might work and might save you the headache of manually patching 5.10 and get you to the desktop much faster OOTB; I'd even be happy to help implement this, but there's only one catch - while I operate RIGOL oscilloscopes on a daily basis, I do not personally own one to run tests on.

It's just a thought for your next build iterations!
Also, thank you for your great work 🫡

Cheers! 🤜🏻 🤛🏻

[norbertkiszka]

Hello.

Sorry for the late reply. I tried multiple different kernels from multiple different sources, including Armbian. I have no idea if this is caused by poor support of RK3399 or bugs in newer kernels or individual changes in the device, but in the best scenario system will boot without working MIPI (internal LCD) and HDMI or it will have only one of those two working with a huge mess on the screen.

Not without a reason I spent around 200 h of work with porting MIPI driver from 4.4.179 to 5.10.209, which I was doing in blind without any guarantee of proper work of this, because my knowledge about DRM subsystem is near zero. Despite of my work with the code which I was unable to understand, it works properly from the first try. Which probably is a result of a pure luck.

[adokitkat]

Hi @norbertkiszka. Have you succeeded in porting the kernel to 5.10.209?

[norbertkiszka]

Hi. Yes it works after some changes and porting MIPI driver from 4.4.179. In Orange-Rigol it needs only few lines changed to make it possible to compile. I didn't finished making all drivers for Rigol hardware related to oscilloscope staff (like internal buzzer connected to GPIO), but what it's now, is perfectly stable.