@mitu said in Display frontend on VGA666 CRT instead of HDMI with Pi4 and KMS:

Thanks for taking the time to answer!

I'm surprised this configuration worked with fkms, but I think it's no longer going to work on kms alone. I've seen your - similar - post on the RPI forums, the definitive answer if this configuration is supported should come from a RP engineer (6by9 is their expert on this).

Yeah, that's the first place I asked. I was hoping it was some stupid mistake on my side.

EDIT: one thing to note, the RetroPie image is currently based on the legacy RaspiOS buster version, a lot of work has been done on the pure KMS driver on the current Linux kernel. You can get the current RP Linux kernel with rpi-update (not recommended) or by manually installing RetroPie on current RaspiOS bullseye (still in beta at the moment), my recommendation would be the latter.

I did try a rpi-update as an extreme attempt, ready to start from scratch. Unfortunately the situation didn't change.

The other idea is to have a second Pi driving the marquee, which is a solution I have mostly working with one last annoying quirk that I wasn't able to iron out yet.
It would be great to do everything from one device though.

I guess you're using the RetroArch master for the switchres support added after v1.15 ?

Yes that's correct. And it seems to work great, possibly much better than the "old" Pi3-style runcommand trickery based on fbset and vcgencmd.

@giandeejay I've been using vulkan on my pi4 64bit bullseye (which uses KMS by default) setup for a while. I only use Retroarch emulators for its crt shaders but I've only noticed better performance with lr-flycast. lr-swanstation (duckstation), and lr-beetle-psx all perform worse than the software renderer. GL renderer was faster in lr-ppsspp. I haven't tried the n64 emulators.