SUMMARY My screen stays black for 30 seconds and only shows a working mouse cursor for 30 seconds after cancelling the screen locking within the "unlock w/o password" grace period. According to journalctl there is a PAM issue and the 30 seconds correlate perfectly: ``` 13:18:12 kscreenlocker_greet: PAM unable to dlopen(/usr/lib64/security/pam_console.so): /usr/lib64/security/pam_console.so: Cannot open the Shared-Object-File 13:18:12 kscreenlocker_greet: PAM adding faulty module: /usr/lib64/security/pam_console.so --- 13:18:12 kscreenlocker_greet: kf.kirigami: Failed to find a Kirigami platform plugin 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:12 kscreenlocker_greet: libpng warning: iCCP: known incorrect sRGB profile 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:12 kscreenlocker_greet: qt.qpa.wayland: Wayland does not support QWindow::requestActivate() 13:18:43 kscreenlocker_greet: QEventLoop: Cannot be used without QApplication 13:18:43 kscreenlocker_greet: pam_unix(kde:auth): unexpected response from failed conversation function 13:18:43 kscreenlocker_greet: QEventLoop: Cannot be used without QApplication --- 13:18:43 kscreenlocker_greet: pam_unix(kde:auth): conversation failed 13:18:43 kscreenlocker_greet: pam_unix(kde:auth): auth could not identify password for [user] ``` STEPS TO REPRODUCE 1. Enable "Automatically lock screen" after 1 minute 2. Set "Unlock without password for" 5 seconds 3. Wait the minute until the screen gets locked automatically 4. Move your cursor within the 5 seconds period SOFTWARE/OS VERSIONS Operating System: Fedora Linux 39 KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.111.0 Qt Version: 5.15.11 Kernel Version: 6.5.11-300.fc39.x86_64 (64-bit) Graphics Platform: Wayland
I reference bug #465266 as it sounds related but there no one reports a black screen.
This issue seems to be related to fingerprint unlocking, as I can short cut the black screen by putting my finger on the fingerprint reader and the last four lines of the log posted in the opening post, namely ``` kscreenlocker_greet: pam_unix(kde:auth): unexpected response from failed conversation function kscreenlocker_greet: QEventLoop: Cannot be used without QApplication kscreenlocker_greet: pam_unix(kde:auth): conversation failed kscreenlocker_greet: pam_unix(kde:auth): auth could not identify password for [user] ``` do not appear in journalctl.
IIRC there's a 30 seconds timeout for the fingerprint reader, which would perfectly correlate. Maybe this issue is fixed in 6.0 where multiple PAM can be used simultaneously but I don't have the time to test this.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/3610
Git commit 2be90db50bd369d44a567e3642ec98deca21187c by David Edmundson. Committed on 28/11/2023 at 11:50. Pushed by davidedmundson into branch 'master'. Fix most of the lock screen The commit introduced the idea of tying the UI to the authentication state. Starting and cancelling as the UI became visible. Whilst nice on paper this had two critical bugs: - cancelling an interactive authentication leads to an entry in the faillock list. This means pressing escape 3 times in quick successsion could lock you out your account for 10 minutes. - There was a concept of a failed state, which wasn't handled in the UI properly leading to prompts disappearing. The notification about the failed lock could not be seen. It also failed to handle the prompts correctly, we had multiple things bound to the same root.notification completely ignoring the handleMessage function which is trying to stack messages. This reverts some of commit 59cdc995e738a0b1cd734e2d1be19e87db99f32b, but keeps the core feature. Related: bug 465266 M +2 -0 lookandfeel/components/WallpaperFader.qml M +22 -17 lookandfeel/org.kde.breeze/contents/lockscreen/LockScreenUi.qml https://invent.kde.org/plasma/plasma-workspace/-/commit/2be90db50bd369d44a567e3642ec98deca21187c