kern/56652: video memory persists through reboot

[yetoohappy%gmail.com@localhost]

>Number:         56652
>Category:       kern
>Synopsis:       video memory persists through reboot
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 22 17:00:01 +0000 2022
>Originator:     yetoo
>Release:        NetBSD 9.99.93 Jan 14 build
>Organization:
>Environment:
NetBSD alarm.lan 9.99.93 NetBSD 9.99.93 (GENERIC) #0: Fri Jan 14 07:40:52 UTC 2022  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC i386
>Description:
Video memory seems to persist through reboots. The last thing displayed on an X server/session can be seen briefly while X server/window manager starts/populates on next boot. I experienced this with a Dell Dimension 2400 and userconf=disable i915drmkms in boot.cfg.
>How-To-Repeat:
1. Disable i915drmkms at boot
2. login to ctwm
3. open a terminal or select the one already open
4. move window around to a non default location or fill terminal window with text
5. execute reboot command (make sure to disable i915drmkms when boot back up)
6. Notice the partially corrupted screen that shows up while x server/window manager starts/populates that shows the terminal with the same text and in the same position moved last boot.
>Fix: