https://bugs.kde.org/show_bug.cgi?id=416720
Bug ID: 416720 Summary: Multiseat with single GPU fails Product: kwin Version: 5.17.4 Platform: Gentoo Packages OS: Linux Status: REPORTED Severity: normal Priority: NOR Component: multihead Assignee: kwin-bugs-n...@kde.org Reporter: lo...@kde.bt.alestan.publicvm.com Target Milestone: --- SUMMARY When Wayland compositors start, they are supposed to limit themselves to only the hardware which is attached to the seat on which the compositor is running loginctl can split the outputs of a single graphics card into multiple seats; these split outputs count as primary devices for seats, allowing them to start up. kwin breaks in 2 ways when trying this. STEPS TO REPRODUCE 1. Set up kwin wayland, with logind or elogind 2. With a multi-output GPU, assign one port to seat1 3. Ask startplasma-wayland to start on seat0; note failure mode 1 4. Ask startplasma-wayland to start on seat1; note failure mode 2 OBSERVED RESULT In the seat0 case, kwin_wayland fails to start. It doesn't matter if there is a monitor attached to the output in question, or which output gets moved to seat1, it fails to start. In the seat1 case, it starts, and grabs all connected screens, regardless of which seat they are assigned. Seat1 doesn't own the tty, so you actually get the mouse cursor *over* the text of the tty, with various repaints fighting back and forth between kwin and the tty shell. EXPECTED RESULT In the worst case, a clear error message that split-gpu multiseat is not supported on KDE. In the ideal case, it should be possible to run a multi-seat setup with a single GPU the same as you can with multiple GPUs. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Gentoo 17.0, Linux 5.3.9 (available in About System) KDE Plasma Version: 5.17.4 KDE Frameworks Version: 19.08.3 Qt Version: 5.12.5 ADDITIONAL INFORMATION -- You are receiving this mail because: You are watching all bug changes.