My PC has a Geforce 980 Ti card and is running Linux Mint 20.1 MATE with Nvidia driver version 460.32.03. The attached displays are a LG LCD monitor on DisplayPort and an Optoma UHD42 projector on HDMI. Screensaver and power management display sleeping are all disabled.
The problem is if I turn the projector off and then later turn it back on it says there is no signal on the HDMI link. PC was continuously left on and not suspended. Three possible solutions I've discovered to get the signal back are:
- Briefly unplugging the HDMI cable from the projector causes linux to reactivate the link and image comes back - but this is undesirable for convenience and wear & tear.
- Briefly unplugging the HDMI cable from the PC also causes linux to reactivate the link but screws up the X Server config and changes the layout - so this is horrible.
- Using the Nvidia Settings app to temporarily change something such as screen resolution reactivates the HDMI link - this is the best I have so far.
I've confirmed this is a linux problem and not the projector (despite its allegedly buggy firmware) because if I boot into Windows 8.1 then it works fine, with Windows detecting the projector turning back on and reactivating the link after blanking the screens for a moment. I also tested the projector on a small Android TV box and again the system interface was immediately shown without issues after the projector finished warming up.
My question is, are there any terminal commands or program code I can execute to force linux to reactivate the link? Or is there perhaps some kind of device I can insert between PC and projector (such as HDMI switch or AV receiver) to trigger link reactivation at the press of a button? Thank you!