Listed as the known issue for v1.1.0 on the Rebuild v1.1.0 wiki page.
What happens
A display plugged in while the board is running is not picked up. The only way to get a picture on it is to reboot with it connected.
A different panel that is already connected at power-on works normally, because U-Boot reads its EDID too - so this is about hotplug, not about which panel is attached.
Why
In v1.1.0 the panel is driven by simpledrm, adopting the framebuffer U-Boot has already set up from the display's EDID. The mode is therefore fixed at whatever U-Boot read at power-on, and on this path there is no KMS driver and no runtime hotplug handling at all.
That is a deliberate trade. It is what gives v1.1.0 one mode from U-Boot through Plymouth to KlipperScreen, with no mode change and no flicker anywhere in the chain, and it replaced a path where the HDMI driver could misread hotplug as low while its PHY came up, invent a 1024x768 mode, and leave the panel blanked for good. Any fix has to keep that.
What a fix needs to do
Detect a display that arrives after boot and bring it up, without reintroducing a mode change on the boot path for the common case of a panel present at power-on. Whatever carries the hotplug has to leave the boot-time framebuffer alone when nothing has changed.
Listed as the known issue for v1.1.0 on the Rebuild v1.1.0 wiki page.
What happens
A display plugged in while the board is running is not picked up. The only way to get a picture on it is to reboot with it connected.
A different panel that is already connected at power-on works normally, because U-Boot reads its EDID too - so this is about hotplug, not about which panel is attached.
Why
In v1.1.0 the panel is driven by simpledrm, adopting the framebuffer U-Boot has already set up from the display's EDID. The mode is therefore fixed at whatever U-Boot read at power-on, and on this path there is no KMS driver and no runtime hotplug handling at all.
That is a deliberate trade. It is what gives v1.1.0 one mode from U-Boot through Plymouth to KlipperScreen, with no mode change and no flicker anywhere in the chain, and it replaced a path where the HDMI driver could misread hotplug as low while its PHY came up, invent a 1024x768 mode, and leave the panel blanked for good. Any fix has to keep that.
What a fix needs to do
Detect a display that arrives after boot and bring it up, without reintroducing a mode change on the boot path for the common case of a panel present at power-on. Whatever carries the hotplug has to leave the boot-time framebuffer alone when nothing has changed.