Bug 2339068 - Temporary black screen when using simpledrm on VM
Summary: Temporary black screen when using simpledrm on VM
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: plymouth
Version: 41
Hardware: Unspecified
OS: Linux
unspecified
medium
Target Milestone: ---
Assignee: Ray Strode [halfline]
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-01-20 22:24 UTC by Mateus Rodrigues Costa
Modified: 2025-12-16 18:27 UTC (History)
3 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2025-12-16 18:27:52 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)
Plymouth debug logs (114.11 KB, text/plain)
2025-01-20 22:25 UTC, Mateus Rodrigues Costa
no flags Details


Links
System ID Private Priority Status Summary Last Updated
freedesktop.org Gitlab plymouth plymouth issues 264 0 None opened Dealing with drm drivers taking a long time to load/probe, enable use-simpledrm by default? 2025-01-20 22:26:21 UTC

Description Mateus Rodrigues Costa 2025-01-20 22:24:39 UTC
One of the recent proposed changes for Fedora 42 is https://fedoraproject.org/wiki/Changes/PlymouthUseSimpledrm, which switches the driver used for plymouth from the actual GPU's driver to simpledrm. One reason this is planned is because some big drivers (such as AMD's) might time out.

However there's is a chance that this change causes a black screen during some part of the boot due to the switch from simpledrm to the actual GPU driver.

As per the thread on https://gitlab.freedesktop.org/plymouth/plymouth/-/issues/264#note_2744540 I was suggested to get debug logs from plymouth to report.

For reference the system is a Fedora Silverblue 41 VM running on libvirt/QEMU.

It's a UEFI system as can be seen on the following excerpt of the XML:

```
  <os firmware="efi">
    <type arch="x86_64" machine="pc-q35-8.1">hvm</type>
    <firmware>
      <feature enabled="yes" name="enrolled-keys"/>
      <feature enabled="yes" name="secure-boot"/>
    </firmware>
    <loader readonly="yes" secure="yes" type="pflash">/usr/share/edk2/ovmf/OVMF_CODE.secboot.fd</loader>
    <nvram template="/usr/share/edk2/ovmf/OVMF_VARS.secboot.fd">/var/lib/libvirt/qemu/nvram/silverblue_VARS.fd</nvram>
    <boot dev="hd"/>
  </os>
```

Kernel parameters are:

```
$ rpm-ostree kargs
rhgb quiet root=UUID=<snip> rootflags=subvol=root,compress-force=zstd:1 rw plymouth.use-simpledrm log_buf_len=50M plymouth.debug=stream:/dev/null ostree=<snip>
```

Reproducible: Always

Steps to Reproduce:
1. Add `plymouth.use-simpledrm` to the boot arguments
2. Reboot and check the plymouth boot

Actual Results:  
A chunk of the boot is a black screen

Expected Results:  
Flicker free boot

Comment 1 Mateus Rodrigues Costa 2025-01-20 22:25:42 UTC
Created attachment 2066824 [details]
Plymouth debug logs

Comment 2 Adam Williamson 2025-12-02 02:11:42 UTC
This message is a reminder that Fedora Linux 41 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora Linux 41 on 2025-12-15.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
'version' of '41'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, change the 'version' 
to a later Fedora Linux version. Note that the version field may be hidden.
Click the "Show advanced fields" button if you do not see it.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora Linux 41 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora Linux, you are encouraged to change the 'version' to a later version
prior to this bug being closed.

Comment 3 Samyak Jain (RedHat) 2025-12-16 18:27:52 UTC
Fedora Linux 41 entered end-of-life (EOL) status on 2025-12-15.

Fedora Linux 41 is no longer maintained, which means that it
will not receive any further security or bug fix updates. As a result we
are closing this bug.

If you can reproduce this bug against a currently maintained version of Fedora Linux
please feel free to reopen this bug against that version. Note that the version
field may be hidden. Click the "Show advanced fields" button if you do not see
the version field.

If you are unable to reopen this bug, please file a new report against an
active release.

Thank you for reporting this bug and we are sorry it could not be fixed.


Note You need to log in before you can comment on or make changes to this bug.