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Bug 1986222

Summary: [RFE] Please turn on SimpleDRM driver
Product: [Fedora] Fedora Reporter: Neal Gompa <ngompa13>
Component: kernelAssignee: Peter Robinson <pbrobinson>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: rawhideCC: acaringi, adscvr, airlied, alciregi, aleixpol, bskeggs, cschalle, csoriano, fmartine, hdegoede, jarodwilson, javierm, jeremy, jglisse, jgrulich, jonathan, josef, kernel-maint, lgoncalv, linville, masami256, mchehab, pbrobinson, ptalbert, rdieter, samuel-rhbugs, steved
Target Milestone: ---Keywords: FutureFeature, Tracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of:
: 1986223 (view as bug list) Environment:
Last Closed: 2021-12-23 11:44:17 UTC Type: Enhancement
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 245418, 1269538, 1277927, 1298494    

Description Neal Gompa 2021-07-27 01:02:51 UTC
Description of problem:
Linux 5.14 introduces the new SimpleDRM driver as a generic fallback driver that supports KMS. GNOME Wayland does not support non-KMS graphics for rendering, and KDE Plasma's non-KMS (fbdev) rendering mode pretty much does not work. This driver makes it possible for desktop environments to *always* expect KMS to work, even if a native driver isn't available, which makes it simpler to support Wayland.

Please enable SimpleDRM so that it becomes achievable to use Wayland for "basic graphics mode" fallback configurations.

Version-Release number of selected component (if applicable):

Additional info:
The lack of this driver led to bug 1952431 happening during Fedora Linux 34's development and I would really like SimpleDRM to be enabled so I can make more progress on solidifying Wayland support and remove hacks to disable Wayland in "basic graphics mode".

Comment 1 Peter Robinson 2021-07-28 12:45:05 UTC
It's not possible to do this as yet. We're working towards getting rid of FB support altogether, as it's unmaintained and obsolete upstream, there's missing pieces here that conflicts with efifb/vesafb/simplefb and other platforms which kills off consoles.

This enhancement gets us the next step there, it's due to land in 5.15:

But that doesn't actually get rid of fbcon as there's no upstream dmscon/kmscon to allow us to remove all of it, that's being worked upon now.

Comment 2 Neal Gompa 2021-07-28 13:03:30 UTC
That mailing list post mentions EFI targets only, what about non-EFI targets for AArch64, armv7hl, POWER, and s390x?

Comment 3 Peter Robinson 2021-07-28 14:17:36 UTC
(In reply to Neal Gompa from comment #2)
> That mailing list post mentions EFI targets only, what about non-EFI targets
> for AArch64, armv7hl, POWER, and s390x?

We're reviewing all. For Fedora use cases all arm, both aarch64/armv7hl are UEFI as of Fedora 34.

In the case of Z/s390x there's no inbuilt graphical console, only serial but we will need to look at how this affects VNC/Virt (not sure it does).

In the case of supported POWER platforms (POWER8 and later) there's no graphical console on the server platforms and early console support on Workstation like Talos2 isn't actually supported at all ATM, basically it's serial output until the desktop loads. I've reached out to some of those people to find out if there's plans around that. Ultimately if their firmware sets up the early console correctly the simpledrm stuff should eventually "just work"

Comment 4 Javier Martinez Canillas 2021-12-23 11:44:17 UTC

*** This bug has been marked as a duplicate of bug 2022385 ***