Re: Fwd: unable to boot when monitor is attached

From: Dr. David Alan Gilbert
Date: Thu Jul 06 2023 - 21:28:42 EST


* Bagas Sanjaya (bagasdotme@xxxxxxxxx) wrote:
> Hi,
>
> I notice a regression report on Bugzilla [1]. Quoting from it:
>
> >
> > In the latest 6.3 and 6.4, it is impossible for me to boot my laptop if my DELL U2720Q monitor is plugged in (USB-C). I have to unplug it, then boot. As soon as the first second of boot went through, I can plug in my monitor and there is no issue afterward. There is no issue waking up after suspend. Only when it boots.
> >
> > See the attached pictures of the trace. The trace itself seems random (at least to me :)). I tried several things, like removing any attached USB devices from the monitor built-in USB-hub, but that does not change anything. (there is a keyboard and trackpad attached).
>
> See Bugzilla for the full thread.
>
> Unfortunately, the reporter can only provide photos of kernel trace
> (as he doesn't have any other means to extract kernel logs, maybe
> connecting over serial helps; see Bugzilla for these attachments).

I note the photos have 'crud' at the bottom; as if something interesting
is in the video ram; perhaps something is freaked out by this nice 4k
monitor and some useful data structures are ending up in video ram.

(Also note it's a librem with pureboot)

Dave

>
> Anyway, I'm adding it to regzbot so that it doesn't fall through
> cracks unnoticed:
>
> #regzbot introduced: v6.1..v6.3 https://bugzilla.kernel.org/show_bug.cgi?id=217637
> #regzbot title: unable to boot with Dell U2720Q monitor attached
>
> Thanks.
>
> [1]: https://bugzilla.kernel.org/show_bug.cgi?id=217637
>
> --
> An old man doll... just what I always wanted! - Clara
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