if you're like me, you may have gotten excited about some DIY handheld games console projects packages out there when you first stumbled to that corner of the web, got the parts, and built the kit.
What they did not mention was that the display the kit came with was a SPI-based one, and as result you're getting 5fps or 10fps or at best 16fps or similar. I was there, and like the rest of you, disappointed by the fact that these displays even exist, and then readily ordered a $20 HDMI display to replace the $15 SPI one, and problem solved.
The slow as crap SPI display was then sitting without function in the corner of my work desk, such a shame, I thought. So I dug a bit deeper into the issue, and last weekend wrote my own display driver for the ILI9341 based display that I have.
You can check out the results of the project at Github: https://github.com/juj/fbcp-ili9341, and a video demo at YouTube: https://youtu.be/h1jhuR-oZm0.
This was a proof of concept project - even with the success, I wholeheartedly recommend people stick to HDMI, since using a generic purpose CPU to run the chore of a dedicated function GPU chip just takes away the precious CPU cycles elsewhere.
Although if you are running an SPI-based display for some reason over a HDMI based one, and are using a "framebuffer cloning" method to display its contents, I'd recommend posting a friendly message or a +1 in this GitHub issue https://github.com/raspberrypi/userland/issues/440 to give more weight to the issue if you think it's worth solving. If that gets resolved, then it's possible that stutter free high refresh rates on SPI-based displays could be developed to become quite power efficient on the Pi.
Hope you liked this!