keyboard not bringing monitor back up after power management or dpms screen suspend

[George Avrunin]

After upgrading to F24, I'm having the following problem.  I have KDE
Settings -> Power Management -> Energy Saving set to turn on "screen
energy saving" after 10 minutes.  This blanks the screen after 10 minutes
of inactivity, as expected.  (xset -q shows that DPMS is enabled, too,
of course.)

Previously, hitting the Alt key or clicking the mouse would bring back the
desktop quickly.  Now (on two different machines), it's not coming back.
But the machine is recognizing the keyboard--I've found that if I do
Ctl-Alt-F2 to switch to a virtual terminal, the monitor quickly shows the
login prompt, and I can go back to X on VT-1 and my Plasma desktop is
there. But hitting other keys (Return, Alt, random letters) doesn't seem
to wake it up.  The monitor acts as if there's no input from the
computer.  It's the DPMS Suspend state that's the problem; the display
comes back when it's in the Standby one.  One of the machines has screen
locking turned on but the other doesn't. 

These are both Dell Precision workstations with Intel integrated graphics,
in case that matters (one with a Dell monitor and the other with a Samsung
monitor).  I didn't (intentionally) change the settings until I started
trying to troubleshoot after the problem arose, so these should all have
been the same as under F23.  I did find an very old bug that might have to
do with this, with a comment from March (747162).  

I tried using xset to turn of DPMS; then the screen doesn't blank at all.
And the same sort of thing happens with the KDE settings version turned
off and DPMS on.  Disabling DPMS means the monitor stays on.  So it's
seems like it's really a problem with DPMS, not the KDE settings.  The
workaround of switching to a VT means this isn't urgent, but it is
annoying. What am I missing?

  George

[George Avrunin]

Some additional information:

- The same thing happens on a very old Dell Inspiron (I think) desktop,
  also with Intel integrated graphics, that my wife uses.  (But the two
  Precision workstations are less than 1.5 years old and the other machine
  is definitely more than 5 years old.  )

- The problem is independent of the display manager (I'm using sddm, but I
  tried with gdm, too) and, mostly, the desktop.  With Gnome, it comes
  back from the initial screen blanking when a key is pressed, but if it
  sits longer it will reach a state where it's necessary to switch to a VT
  and back to get back to the X display.  

- The machine is seeing other key events, too, but they just don't wake up
  the display. If I leave the focus in, say, a konsole or a Gnome terminal
  and let the machine blank the screen (waiting long enough on Gnome),
  typing ordinary text won't bring back the display but the typed material
  shows up when I switch to a VT and switch back. 

- I tried with a new user, in case this had something to do with settings
  getting upgraded from F23 to F24 or some other misconfiguration in my
  account.  But the same thing happens.  

Is anyone else seeing this?  Should I file a bug?  For X, for the Intel
driver, or something else?

  George

[Lester Petrie]

On 7/4/2016 3:12 PM, George Avrunin wrote:
>  Some additional information:
>
>  - The same thing happens on a very old Dell Inspiron (I think) desktop,
>    also with Intel integrated graphics, that my wife uses.  (But the two
>    Precision workstations are less than 1.5 years old and the other machine
>    is definitely more than 5 years old.  )
>
>  - The problem is independent of the display manager (I'm using sddm, but I
>    tried with gdm, too) and, mostly, the desktop.  With Gnome, it comes
>    back from the initial screen blanking when a key is pressed, but if it
>    sits longer it will reach a state where it's necessary to switch to a VT
>    and back to get back to the X display.
>
>  - The machine is seeing other key events, too, but they just don't wake up
>    the display. If I leave the focus in, say, a konsole or a Gnome terminal
>    and let the machine blank the screen (waiting long enough on Gnome),
>    typing ordinary text won't bring back the display but the typed material
>    shows up when I switch to a VT and switch back.
>
>  - I tried with a new user, in case this had something to do with settings
>    getting upgraded from F23 to F24 or some other misconfiguration in my
>    account.  But the same thing happens.
>
>  Is anyone else seeing this?  Should I file a bug?  For X, for the Intel
>  driver, or something else?
>
>    George 
Yes, I see this also. I have a Dell desktop with AMD graphics. I have 
turned screen blanking off, so that my screen saver runs all the time 
after my machine goes idle. I hadn't discovered that switching to a VT 
and back would activate the screen. I will have to give that a try.

-- 
Lester M Petrie
lmpetrie(a)bellsouth.net

[George Avrunin]

On Mon, 4 Jul 2016 15:25:27 -0400, Lester Petrie wrote:

>  Yes, I see this also. I have a Dell desktop with AMD graphics. I have
>
>  turned screen blanking off, so that my screen saver runs all the time 
>  after my machine goes idle. I hadn't discovered that switching to a VT 
>  and back would activate the screen. I will have to give that a try. 
It seems to have come with the 4.6 kernel.  I should have thought of
trying this before (thanks to Tom Horsley in a thread on "Really excessive
screen behavior" for reminding me!) but with kernel-4.5.7-300.fc24.x86_64,
this doesn't arise.  So for now I'm just back to booting to the older
kernel.  

This doesn't seem to be the same as any of the other bugs I could find, so
I've entered it as a new one,
https://bugzilla.redhat.com/show_bug.cgi?id=1352719

I entered it for the kernel, though maybe it's really an X11 or driver
bug.  Someone with a lot more knowledge of the internals than I have will
have to decide that. 

  George