Bug 1175994

Summary:	Boot freezes for 5.7.1-1 and 5.8.4-1
Product:	[openSUSE] openSUSE Tumbleweed	Reporter:	Michael V <michael>
Component:	Bootloader	Assignee:	Kernel Bugs <kernel-bugs>
Status:	NEW ---	QA Contact:	E-mail List <qa-bugs>
Severity:	Critical
Priority:	P5 - None	CC:	michael
Version:	Current
Target Milestone:	---
Hardware:	Macintosh
OS:	openSUSE Tumbleweed
Whiteboard:
Found By:	---	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---
Attachments:	Hardware information collected by YaST Snap of boot errors.jpg

Description Michael V 2020-09-01 09:55:09 UTC

User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:79.0) Gecko/20100101 Firefox/79.0
Build Identifier: 

After upgrading from 5.6.14-1-default using `zypper dup` I couldn't boot and had to boot with the old kernel. The issue happened in two subsequent minor versions.

Reproducible: Always

Steps to Reproduce:
1. Upgrade from 5.6.14-1-default
2. Restart machine
3. Select 5.7.1-1 or 5.8.4-1 on grub
Actual Results:  
 - Loads initial RAM disk
 - mentions IOMMU errors (happens with previous kernel too)
 - boot freezes
 - second screen isn't activated (that's how I know it's frozen)

Expected Results:  
 - Loads initial RAM disk
 - mentions IOMMU errors (happens with previous kernel too)
 - activate second screen
 - show splash screen

I cannot test with patch version of 5.6.x since Tumbleweed doesn't provide them anymore.

`journalctl` doesn't have any logs of the failed boots. It doesn't seem as if it gets that far, but I'd be happy to try and get debug logs if instructions are provide on how to do so.

My camera is trash (thank you OnePlus) so, I'll jot down the logs before it freezes and post them later.

Comment 1 Michael V 2020-09-01 10:07:01 UTC

Created attachment 841231 [details]
Hardware information collected by YaST

Comment 2 Michael V 2020-09-02 14:04:53 UTC

Created attachment 841295 [details]
Snap of boot errors.jpg

ACPI Error: Need type [Reference], found [Integer] ... (20200528/exresop-66)

ACPI Error: AE_AML_OPERANT_TYPE, While resolving operands for [Store] (20200528/dswexec-431)

ACPI Error: Aborting method \_PR.CPU0._PDC due to previous error (AE_AML_OPERANT_TYPE) (20200528/psparse-529)

Comment 3 Michael V 2020-09-04 15:06:29 UTC

After following [Debugging boot hang](https://en.opensuse.org/SDB:Debugging_boot_hang) and replacing `quiet splash=quiet` with `debug initcall_debug`, the system gets all the way to

```
fb0: switching to inteldrmfb from EFI VGA
```

and just hangs there. No keyboard input accepted. Only hard reboot with power button works. Note again that this happens **only** with kernels above 5.6.14-1.

Somewhere else I found that nomodeset might help and it does to some degree. It boots, but the second screen doesn't work and I can't change the resolution of the main laptop screen.

There was a regression somewhere and I have no idea how to bisect a kernel. I have a debug kernel also installed, but I don't have the foggiest on how to use that yet.