Selecting Display > Resolution does not work - returns to the main menu

[dankcushions]

I am unable to select the Resolution menu as it always quits back to the main menu immediately. This is via Raspi OS Lite 5.10.11-v7l+.

Potentially relevant parts of config.txt:

# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=2
hdmi_mode=82

(i have to manually select HDMI modes otherwise it defaults to 4k which has bad performance - if I remove these lines it still fails)

dtoverlay=vc4-fkms-v3d
max_framebuffers=2

[all]
overscan_scale=1

[BenMcLean]

Is there anything we need to do to get this crippling problem some attention?

[XECDesign]

@spl237

[spl237]

The resolution menu in raspi-config is only usable with legacy mode video drivers; with the KMS driver which is now standard, the command-line xrandr tool should be used instead. This option shouldn't be shown in the raspi-config menu any more; I will remove it.

[spl237]

Also - you should not be using the line dtoverlay=vc4-fkms-v3d on any of our images any more - that loads the fake KMS driver, which is no longer supported. That line should either be ...vc4-kms-v3d, or it should be absent altogether to access the legacy video driver, but that is not an option on Pi 4 or Pi 400, which have to use KMS. What you have in your config.txt looks unsupported to me.

[lurch]

you should not be using the line dtoverlay=vc4-fkms-v3d on any of our images any more - that loads the fake KMS driver, which is no longer supported.

Oh! I didn't know that.
Does that means that this and this needs updating Simon? (ping also @aallan as I guess this also impacts raspberrypi/documentation#2310 )

[spl237]

Err - pass. All I know is that I have modified raspi-config so that the only GL driver options are KMS on Pi 4 / 400, and KMS or legacy on older Pis. fKMS is not available in raspi-config any more, so my understanding is that people should not be using it; it still works (presumably...), but I don't think future support for it is guaranteed. Worth checking the official position with GH or similar rather than taking my word for it though...

[spl237]

But yes, at a quick look, those pages are definitely out of date - the KMS driver is now the default and is no longer experimental, for a start.

[aallan]

I guess this ties into raspberrypi/documentation#2310 and also raspberrypi/documentation#2061

[dankcushions]

The resolution menu in raspi-config is only usable with legacy mode video drivers; with the KMS driver which is now standard, the command-line xrandr tool should be used instead. This option shouldn't be shown in the raspi-config menu any more; I will remove it.

xrandr only works in X11, no? I am not using X or FKMS - I am using KMS with command line content that goes straight to the framebuffer (https://github.com/RetroPie), by default using the global display mode in config.txt. this is what this resolution option in raspi-config adjusts, and it used to work fine.

could raspi-config not be updated to update display mode at runtime via KMS? it would be a very useful tool for non-X environments.

[XECDesign]

This is looking like a wontfix. I don't think there's going to be effort made to support resolution setting for legacy or FKMS. If there's a way to get raspi-config to adjust resolution on the fly with KMS that works with or without X, that would be great, but sounds like a separate issue.

[dankcushions]

Fair, though rather than just exit out and do/say nothing, it would be better in the scenario of KMS + outside of X that the option adjusted config.txt, but prompted for a reboot.

[BenMcLean]

Fair, though rather than just exit out and do/say nothing, it would be better in the scenario of KMS + outside of X that the option adjusted config.txt, but prompted for a reboot.

Since the active devs want to not spend time on this (totally understandable) I brought up the idea of just removing the Resolution menu altogether over here.

[spl237]

The option has already been removed for the next release.