Wayland By Default in KDE
Change the default session selection in SDDM to prefer the Wayland-based Plasma session over the X11-based one.
- Name: Jan Grulich
- Email: <email@example.com>
- Release notes owner:
- Targeted release: Fedora 28
- Last updated: 2018-01-15
- Tracker bug: <will be assigned by the Wrangler>
We will change SDDM to use wayland by default for Plasma. We will also attempt to automatically fall back to Xorg in cases where wayland is unavailable (like nvidia). There will still be option to use Plasma session on Xorg to those who don't want to switch to Wayland yet.
Benefit to Fedora
Using Wayland instead of X gives much better basis for isolating applications from each other and the system.
- Proposal owners:
- Make SDDM to use wayland session as default.
- Make sure that wayland session is working as good as X11 session and there is no big feature gap for regular user usage.
- Other developers:
- Qt applications that rely on X11-specific API need to be patched to work under Wayland.
- Release engineering: #Releng issue number (a check of an impact with Release Engineering is needed)
- List of deliverables: N/A (not a System Wide Change)
- Policies and guidelines: N/A (not a System Wide Change)
- Trademark approval: N/A (not needed for this Change)
Systems using certain graphics hw or graphics drivers (matrox, qxl) may have problems running the Wayland session. In these (rare) cases, users may have to configure SDDM to use X11 (although automatic fallback should work most of the time). If we don't manage to close all the feature parity gaps entirely, then users relying on those features may have to choose the X11-based session.
How To Test
- Boot a fresh F28 KDE Spin install.
- Verify that the session chooser offers 'Plasma', 'Plasma (Wayland)', and that 'Plasma (Wayland)' is selected by default.
- Log into 'Plasma (Wayland) and verify that it gives you Wayland (you can verify this by opening any KDE app and going to Help → About "app" and checking that it says "Wayland windowing system").
- Log into the Wayland-based session again
- Use the desktop normally, and verify that there are no obvious instabilities, or Wayland-specific bugs or performance problems
- Choose 'Plasma' session (X11 based one)
- Verify that X11 session is still working for those who don't want to use or can't use Wayland session
The user experience of the Wayland session is identical to that of the X session.
The tasks lists in the Scope section are spread across a number of upstream modules and packages: qt5-qtbase, qt5-qtwayland, plasma-workspace, kwin, kf5-kwayland, sddm.
- Contingency mechanism: Change back that 'Plasma' session will be used by default instead of 'Plasma (Wayland)' and offer 'Plasma (Wayland)' session on the spin as a secondary option.
- Contingency deadline: beta
- Blocks release? no
- Blocks product? no
N/A (not a System Wide Change)