Intel HD 770 (AlderLake-S GT1) embedded GPU causes blank screen even with kernel 5.17

sunbeam60

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Hi, I've installed Ubuntu 22.04 on an Intel 12700T (AlderLake) but the screen goes black when switching to the i915 (Intel eGPU) driver.

  • This happens in the 22.04 Desktop setup (which only run in "Safe Graphics" model),

  • It happens when 22.04 Desktop boots normally.

  • It happens in 22.04 Server setup (which only works when Grub is seeded with additional GRUB_CMDLINE_LINUX_DEFAULT="module_blacklist=i915")

  • And it happens in 22.04 Server boot where, just after the boot spew says "fb0: switching to i915 from EFI VGA", the screen goes black.

lshw clearly recognizes the device:
*-display UNCLAIMED
description: VGA compatible controller
product: AlderLake-S GT1

Now, evidently the 5.15 that 22.04 ships with doesn't support AlderLake eGPUs ... so, my thinking was "install 22.04, then upgrade the kernel to 5.17, where AlderLake eGPUs are meant to be fully supported".

This I've done; I blacklisted the i915 driver to get the install and regular boot working for Ubuntu 22.04 and now upgraded to 5.17:
~$ uname -r
5.17.0-051700-generic

... but when taking the i915 driver off the black list after the kernel upgrade, I STILL get a black screen after the "fb0: switching..." message during boot.

I know my computer operates ... if I type username, password and then "reboot -r now", the system reboots. Additionally, if keeping the i915 driver blacklisted, everything works fine; except the display adapter stays "UNCLAIMED" and /dev/dri/renderD128 are unavailable.

So there's a working shell in there, and a functioning system. But I cannot get anything valid out of the i915 driver, despite claims of full Alder Lake support from 5.16+.

I'm keen to get the i915 driver working as I need the eGPU for a video transcoding task.

Does anyone have any advice on how to proceed?
 
Last edited:


Well, as a follow-up, removing the i915 module blacklist but using ssh to get onto the box, the /dev/dri/renderD128 device is there, the AlderLake S-GT1 eGPU is no longer unclaimed. It all seems to work, except there's zero output to an actual physical screen.
 

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