On 6/18/22 20:10, Fulko Hew wrote:
On 6/2/22 09:08, stan via
users wrote:
> On Wed, 1 Jun 2022 10:54:50 -0400
> Fulko Hew<fulko.hew@gmail.com>
wrote:
>
>> I just had it again, it's very rare.
>> And it's happened over the last number of Fedora
versions (-1 to -n)
>>
>> If I come back to use my computer and hit a key at
exactly the same
>> time as the screen decides to blank (I don't use
screensavers) then
>> the screen does blank, but no key or mouse activity
(I've tried) will
>> cause the screen to wake up again. I know the
machine is still
>> active because one of the keystrokes I tried, woke
up and started to
>> play a Youtube video that was paused on one of my
browser instances.
>>
>> So everything is still working, but nothing (I've
found) will
>> un-blank the screen.
>>
>> Idea's anyone?
>>
>> [It's hard to replicate, but I seem to be able to
time it right/wrong
>> every few months.]
> What you describe is being caused by a race condition
of some kind.
> The screensaver is not using locks to ensure atomic
actions. So, two
> events are occurring at roughly the same time, and
depending on which
> one wins the race, the screen recovers or thinks it is
already
> recovered, even though it is blank [blank loses the
race]. You could
> open a bugzilla against the screensaver, just so they
are aware of the
> issue. It probably won't get fixed on its own, but if
they are in the
> code anyway for something else, they might look at this
too, if they
> know about it.
>
> Have you tried switching to a virtual console,
Ctl-Alt-F[3-6]?
> That should trigger a context switch to the framebuffer
driver, which
> refreshes the monitor. Then, if you switch back to the
gui, usually
> Ctl-Alt-F1, the context switch back to the desktop
should initialize
> things properly, because it thinks it is already
active. Worth a
> try, but no guarantees. The virtual consoles have been
losing
> functionality [1] as fewer and fewer developers use
them, and recently
> started using simplefb from the kernel, so I'm not sure
if that might
> not short circuit any context switching.
>
> 1. The latest was losing the scrollback buffer. That
meant that
> screen lost its scrollback as well. I really miss it,
any one know of a
> user space replacement, I'm tired of typing ' | less'
after everything,
> the second time, when things scroll off the screen the
first time. :-)
> Searching hasn't turned up a viable alternative.
> _______________________________________________
Can use pkill, pgrep to query and restart the gui from the
virtual console.
Except that when this happens, I don't
think I can switch to a
virtual console. Or at least if I
did, the screen is still
blanked and I'd be typing blind.
Terminology problem. Ctl-Alt-F[3-6] gives you a command line
session that is completely separate from your original. Requires
login.
Yes, I am aware of that. It was the 2nd thing I tried.
No matter what keystrokes I tried including screen switches,
I could not get anything that would light up the screen again.
Are you using vncserver started by systemd?
I normally use VNC on servers so I can work from one workstation. Recently the workstation
had an SSD fail. When I tried logging in on a server, I got a blank screen. <Ctrl-Alt-FN> for
N>1 all gave blank screens, but
<Ctrl-Alt-F1> got me back to the login screen where I could
log in as a different user and kill the vncserver for my regular login.
I've had monitors with multiple inputs that would switch to the other input when the screen
blanked and require manually switching back using the buttons on the monitor. This was a
while ago, but I suspect a KVM may have been involved.
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