Set desktop to RGB565 instead of RGB8888 on mainline kernel?

[Larry Bank]

For a project, I need the Linux desktop to be set to 16 bits per pixel. I can't find any documentation about how to do this on the mainline kernel. Anyone?

[jernej]

3 hours ago, Larry Bank said:

For a project, I need the Linux desktop to be set to 16 bits per pixel.

That format is not yet supported by mainline driver (http://elixir.free-electrons.com/linux/latest/source/drivers/gpu/drm/sun4i/sun8i_layer.c#L64). Fortunately, it is easy to add support. In the aforementioned array add DRM_FORMAT_RGB565 and here http://elixir.free-electrons.com/linux/latest/source/drivers/gpu/drm/sun4i/sun8i_mixer.c#L69 add:

case DRM_FORMAT_RGB565:
		*mode = 10;
		break;

Currently I'm working on a improved DE2 DRM driver, which will include this.

 

However, I'm still not sure how to make that default choice. But first it must be supported by the driver

[Larry Bank]

Thanks for the info. I have no idea how to modify/integrate the driver changes into my setup. I can work around the issue for now (with a performance hit), but it's good to know it will eventually be resolved. Eventually I guess I need to build Armbian from source so that I can experiment with things like this.