Fwd: 6.1.23: 0fc6fea41c71 breaks GPD Pocket 3 modeset

From: Kurt Garloff
Date: Sat Apr 29 2023 - 17:42:12 EST


Hi Ville,

(sorry for the resend, had forgotten that LKML still believes
that multipart with an HTML version is evil)

While
0fc6fea41c71 drm/i915: Disable DC states for all commits
(cherry picked from commit 41b4c7fe72b6105a4b49395eea9aa40cef94288d)
does look correct to me, it does break modesetting on the
GPD Pocket 3, a i7-1195G7 laptop. I run the kernel with
fbcon=rotate:1 video=DSI-1:panel_orientation=right_side_up \
  mem_sleep_default=s2idle
No special i915 parameters.

Hardware is described here:
https://wiki.archlinux.org/title/GPD_Pocket_3

I disected this patch which was merged (backported) for 6.1.23.
I currently run 6.1.26 with it reverted and life is good.

Without reverting it, when fbcon is switched to show the splash
screen (GPD logo with Ubuntu added in on working kernels), the
screen remains black (backlight on, but nothing displayed) and
nothing happens any more. It looks like something more serious
than just blackness, as SysRq or Ctrl-Alt-Del don't do anything.
Deadlocking?

Best,

--

Kurt Garloff<kurt@xxxxxxxxxx>
Cologne, Germany