Well I’m finding out that this computer has a bug. If I leave it with its screen-locker locked for some time, and then unlock with my password, the unlock dialog seems to succeed, but only reveals a black desktop, with only the mouse-pointer visible.
I suspect that I know what causes this. The computer in question has an old ‘Intel 910′ graphics chip-set, and although it may be good the the chip-set is supported, that chip-set and its drivers have quirks. I do have OpenGL 1.4, which should be high enough a version. But it may be that ‘behind the screen-locker’, by the time I’ve unlocked the machine again, the ‘Compiz Fusion’ desktop compositor has crashed.
There are certain other quirks which point to a graphics chip problem:
- The window title-bars sometimes don’t render, until I click in the region where the title-bar should be, in which case they reappear.
- Wobbly Windows needs to be enabled, in order for me to be able to restore the title-bars in this simple way.
I found that a practical way to deal with this not-resuming from the screen-locker, may be, by setting the key-sequence <Ctrl>+<Alt>+<Backspace> just to kill the X-server, as it would do under KDE or Plasma 5, using the following customization. I can right-click on the Keyboard Layout Tray Icon, then left-click on “Keyboard Layout Handler Settings”, and then:
I have set 2 ‘setxkbmap Options':
- The Compose Key,
- The X-server kill key.
Killing the X- just prompts me for a log-in again.
There is some possibility that the Compiz crash, on resuming from a plain lock-screen, may have to do with the Compiz setting, to display a Splash Image. By default, Kanotix systems come with an animated Kanotix splash-screen, that may look nice on systems with stable graphics, and for the first few times the system is explored. We can change this splash-screen to something other than the Kanotix splash-screen.
But I have noticed that, just for Compiz to start the splash-screen, causes instability with the Intel 910 chip-set, even if it does work. So what may be happening, is that on resuming from the lock-screen, Compiz may be programmed to display the splash-screen, and doing so may be what crashes my session. And so for now, I’ve also disabled this feature, and will comment later, on whether having done so has fixed the crashes.
(Update 09/05/2018, 15h30 … )
(As of 09/02/2018 : )