Hi,
Replying to old thread since Google brought me here while looking for a way to scale resolutions with the GPU, and also because I noticed it was not solved for OP - and there’s a slim case my post will.
However, I got it working with:
Option "IncludeImplicitMetaModes" "DisplayDevice = HDMI-0, Scaling=Aspect-Scaled, UseModePool = false"
I’m not sure this will help the OP; I’d guess it is either a wrong displaydevice (in my case “DisplayDevice = HDMI-0”), OR (just guessing) UseModePool does not do what it says in the documentation? I thought (without reading the documentation) that in case it is set to true, modes that the display is reporting will be set in HW instead of being scaled. But according to documentation this is not the case. However, by default (or with just Option “IncludeImplicitMetaModes” “True”), all modes were set in HW instead of being scaled by GPU. I haven’t tested which option makes it work in my case, but if I have the time, I will test it later on.
IMO this should be easier. According to Google, the most common use case is when attatching a laptop to a projector and wanting to use a clone mode. There are still a lot of 4:3 projectors out there and this should really be easier; I don’t usually use clone mode, but if I want to / someone borrows my laptop who wants to, this will come in handy, as most laptops don’t have any options in the display device itself.
In any case, I (also) needed this for retro gaming since my TV (which I use ATM) has poor control over 4:3 resolutions, and hence they need to be scaled to the native resolution of the TV one way or the other.
HTH,
Cheers!