Re: kern/60140: NetBSD 11.0-RC2 boots to black screen on Thinkpad X240 more often than not

["opensauce04%gmail.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR kern/60140; it has been noted by GNATS.

From: opensauce04%gmail.com@localhost
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/60140: NetBSD 11.0-RC2 boots to black screen on Thinkpad
 X240 more often than not
Date: Sun, 29 Mar 2026 17:17:39 +0100

 > The following reply was made to PR kern/60140; it has been noted by GNATS.
 >
 > From: Robert Elz <kre%munnari.OZ.AU@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 > Cc:
 > Subject: Re: kern/60140: NetBSD 11.0-RC2 boots to black screen on Thinkpad X240 more often than not
 > Date: Sun, 29 Mar 2026 22:09:43 +0700
 >
 >       Date:        Sat, 28 Mar 2026 22:40:02 +0000 (UTC)
 >       From:        "opensauce04%gmail.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>
 >       Message-ID:  <20260328224002.2FBE61A923E%mollari.NetBSD.org@localhost>
 >   
 >     |  Could someone update that, and also maybe update the PR title to reflect
 >     |  the charging thing if possible?
 >   
 >   I have done that.
 >   
 >   When you say "boots to black screen" do you mean doesn't boot at all?
 >   
 >   The boot process should start writing some (usually green) text to
 >   the monitor, using the firmware to access the display) - and then
 >   eventually take over the display (you can often see the font change)
 >   and continue writing more configuration info (you will have seen all
 >   of this on the successful boots).
 >   
 >   If none of that happens, the boot isn't being successful at all (probably
 >   the kernel is being loaded, those are the "writes some numbers", but after
 >   that something hangs, or similar).
 >   
 >   If it reaches the point where the video should switch, and the screen
 >   just goes black instead, then that's an entirely different class of problem.
 >   In that case, if you can (from elsewhere - even from a phone) see if you
 >   can access the system (can you ping it) - if so, that would indicate it
 >   is running OK, and just the video is not functioning.   If it isn't responding
 >   then the boot failed somehow.
 >   
 >   Which of these is happening would be useful info to find the right person
 >   to help you work out what the issue really is (all I can say about that now
 >   is that I will not be that person).
 >   
 >   kre
 
 On failed boots, there is none of the usual green text. Numbers are 
 printed to the screen in a white font, and then the laptop screen just 
 goes blank and nothing ever happens. The laptop and its screen are still 
 powered on, it's just black.
 
 On successful boots, the usual green text appears, and I get dropped 
 into a TTY login prompt as expected. The system works completely fine 
 after this point.
 
 To clarify, whether or not the charger is plugged in only matters during 
 the boot process. I can unplug the charger, wait for it to boot, and 
 then plug the charger back in, and everything is fine, but if it's 
 charging *during the boot process*, it has an extremely high likelihood 
 of failing.
 
 I have no desktop environment installed on this device, and as I 
 mentioned, this also happens with flashed USB installers, which also 
 have no graphical environment.
 
 I am unable to ping the laptop when the boot fails, but can ping it 
 successfully without logging in when the boot is successful. Definitely 
 seems like NetBSD is failing to boot rather than it being any video issue.