"Out of memory" errors on NovaThor U8500 devices

On (probably?) all NovaThor U8500 devices, certain applications, games, and such crash. What follows are @nergzd723's findings, mainly as I don't want them to get lost, but also to have somewhere to track progress on this issue.

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So I've been investigating why KDE UI's and GPU-heavy games crash on my device, and it turns out they both display "DRM_IOCTL_MODE_CREATE_DUMB failed: Out of memory" before a crash.

This probably means GPU cannot allocate enough memory for itself, so I dug deeper and added a following node to reserved-memory:

linux,cma {
	compatible = "shared-dma-pool";
	reusable;
	size = <0x10000000>;
	alignment = <0x2000>;
	linux,cma-default;
};

and now I can run supertuxkart and Retroarch in Plasma Desktop without any issues or crashes :)

What's a proper fix to this? just reserving 256MiB of memory for GPU doesn't sound like a good thing, although reusable property will make it accessible to normal applications too, but it's still quite ugly. I'm also not sure why it happens in the first place, considering that PinePhone or other devices don't allocate any memory and they're fine. also I want to remark that there was always free ram when the Out of memory issue happened.