[clug] Laptop Problem

[Duncan Roe]

Hi Brett,

On Thu, Mar 04, 2021 at 11:53:12AM +1100, linux wrote:
> Hi all.
>
> My laptop is dead!  It's a Dell 9550 XPS 15 running Kubuntu 20.11.
>
> Yesterday I noticed that the screen was not blanking when the screen lock
> activated.  It looked like something that might cause burn-in so needed to
> be addressed.  I checked the power settings and all seemed OK there.  I had
> an outstanding reboot to activate a kernel upgrade so I thought I'd just do
> that to see if it fixed the screen blanking problem.
>
> That's when it all went bad.
>
> Now I get the Dell splash screen immediately followed by the screen going
> black (no backlight) followed by the backlight coming on but nothing on the
> screen.  After a few seconds the CPU fan starts ramping up so the cpu is
> just spinning.  I have tried hitting escape over and over to see if I could
> break into grub but it will not.  The keyboard buffer just fills and beeps
> rudely at me.
>
> When I get home I plan to look at it again by booting an iso and see if the
> disk looks OK.  The Dell diagnostics run to completion without error.
>
> So my questions are:
>
>        Could it be that the system is seeing a bogus suspend state at boot
> and loading garbage?
>        How does that work?  i.e. How does the BIOS know to just unsuspend?
>
> If it was just trying to unsuspend then I should not be seeing the Dell
> splash screen.  So perhaps it thinks it's waking from hibernation?  Now is
> unhibernate triggered?
>
> Anyway I just thought I'd rant about it so I don't cry about it.
>
> --
> Brett
>
>   /) _ _ _/_/ / / /  _ _//
>  /_)/</= / / (_(_/()/< ///
> --

You don't mention to which Linux version you were upgrading.

Can you still boot the previous kernel? I would try that, if you can.

My laptop fails to boot 5.10.x kernels. Until, that is, I revert a 1-liner
commit (presumably breaking whatever that commit fixes). I submitted
https://bugzilla.kernel.org/show_bug.cgi?id=211041 but there has been no
activity on it other than my own.

My laptop also fails to boot 5.11.x kernels. Using git bisect, I have found 2
seperate syndromes which stop it booting. And the CPU fan does rev up, as you
describe. I have yet to submit a bug report pending further investigation.

HTH,

Cheers ... Duncan.