The lock service arms a 5s blank timer whenever the screen locks, and
input at the lock screen re-arms it. Closing the lid sprays pointer
noise over the lock surface, so the timer was routinely armed right
before suspend, froze mid-countdown, and fired moments after resume --
blanking the freshly woken unlock screen under the user.
Guard the timer with a wall-clock check: if far more time elapsed than
the interval, the countdown slept through a suspend, so take a fresh
run-up instead of blanking. This also blanks the lock screen 5s after
an untouched resume.
Two accomplices made the flash worse and hid the real bug:
- The clamshell watcher's 2s poll fired an unconditional global DPMS
enable whenever no external monitor was active, relighting any blank
within 2 seconds (lock-screen blanking never stuck on undocked
laptops) and racing the resume modeset. Recovery now only wakes
displays when it actually re-enables one.
- Every keystroke at the lock screen dispatched a redundant DPMS
enable via omarchy-system-wake, forcing extra modesets in the
fragile just-resumed DRM state. Brightness "on" now skips the
dispatch when every active display is already lit.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
