On Tue 27 Aug 2024 at 14:58:14 (-0400), gene heskett wrote: > On 8/26/24 14:37, David Wright wrote: > > On Mon 26 Aug 2024 at 10:29:10 (-0400), gene heskett wrote: > > > xfce4 desktop, running linuxcnc, [ … ] > > > came across a dangerous situation yesterday. > > > > > > Basically using the lathe as a jig to hold a long piece I was tapping > > > by hand, powered up but stopped. screen blanker came on and locked me > > > out till I logged back in leaving linuxcnc live but hidden behind a > > > black screen. This is a dangerous condition if he wrong key is hit to > > > wake it up. > > > > Surely it's not screen /blanking/ that's your problem¹ but screen > > /locking/. BTW were you really logging back in, or just unlocking > > the session? > > total login to get back to my session.
How did you distinguish between the two cases? > > > That monitor AND the idling rpi4b draw about 22 watts, and is turned > > > off only for maintenance. UPS, standby generator, uptimes might be > > > years. > > > > > > Replacing a CRT power hungry monitor means the only reason to blank a > > > screen > > > > tomas mentioned xset, which should deal with that. You need to decide > > on whether a couple of seconds is too long to wait for recovery from > > anything more than simple blanking. > If the machine starts, while trying to wake it up and log back in to > get control back to me, its already 5 seconds too damned late. With > the pi, wakeup time is 5 + seconds by which time a sleeve caught on a > chuck jaw has already tried to rip an arm off. Agreed, but my paragraph was distinguishing between simple blanking and powersaving. (Of course you don't want to be typing a password.) In the past, I found the instant recovery from blanking (with no powersaving) was quite satisfactory, while preventing burn-in from being run 24/7. (This was in a lab with restricted access.) > > > and interpose a login is security against prying eyes in an > > > office environment. > > > > That's the troublesome one for you. > > Absolutely. This is not an office environment. The path thru this > garage is hardly wide enough for me, let alone company. There are plenty of google hits on this topic, some posted by people who get fed up logging in over and over again in meetings. Various OSes plus xfce.org itself. Have you made any progress yourself? I get the impression > > > Soooo, what do I remove to absolutely, permanently disable the screen > > > blanker? And I mean no chance it can ever do that to me again. There are odd reports of a very long timeout working better than Off. Perhaps bear that in mind. > > AFAICT you need to investigate XFCE's Power Manager. A quick google > > turned up these: > > https://forum.manjaro.org/t/how-to-disable-auto-black-screen/127827/2 > > https://forum.xfce.org/viewtopic.php?id=13535 > > https://forum.manjaro.org/t/lock-screen-vs-login-screen/166644 > > but there may be better ones too. On Mon 26 Aug 2024 at 15:42:56 (-0400), Felix Miata wrote: > David Wright composed on 2024-08-26 14:36 (UTC-0400): > > > ¹ touch Ctrl, the key at the extreme bottom left of the keyboard, > > to defeat it. > > Are you sure? Well, all four of the laptops in this house, the previous two we disposed of, and all the assorted keybords I've acquired over the last twenty years or so. But finding the safest key to use may be irrelevant if Gene doesn't trust even basic screen blanking to occur (see above). Cheers, David.
