[xubuntu-users] restarting window server or possibly usb service remotely

[Dan Hitt]

Thanks Roger for your response, replies interspersed:

On Sun, May 8, 2016 at 1:46 PM, Roger <linux.rog at gmail.com> wrote:
> Can you used an F key that switches from one monitor to overcome the
> difficulty?

Yes, that's the workaround based on Victor's response:

Control-Alt-F1 to get to to a virtual terminal, then power off monitor.

On return, power-on monitor, then Control-Alt-V7 to get to x windows.


>
> What kind of cable / "monitor" do you have? I have a monitor that can serve

HDMI.

https://en.wikipedia.org/wiki/HDMI

The wikipedia article says it is proprietary which i did not know.

It works fine with Ubuntu 15.10 (and several earlier versions), but
i've run into a couple of issues with xubuntu 16.04.

> as a TV. It even has a remote control. I had to get a DVI cable to make my
> monitor work correctly, from Amazon:
>
> http://tinyurl.com/hdn7ss9
>
> Some times things are just weird!
>

They sure seem to be, but hoping to get some light shed on this one.

dan

>
> On May 8, 2016 3:57:47 PM EDT, Dan Hitt <dan.hitt at gmail.com> wrote:
>>
>> Ah Victor thanks a million!
>>
>> Turning off the monitor turns out to be key.
>>
>> If i turn off the HDMI monitor, lightdm (or whatever the underlying
>> service is) seems to take that as a signal to never return.
>>
>> So that means that there is a work around.  First, do ctrl-alt-f1 to
>> get into a virtual monitor.  Then turn off the monitor.
>>
>> And coming back, just do the reverse: turn on the monitor, then do
>> ctrl-alt-f7 to get back xwindows.
>>
>> This is possibly related to another problem that i have, where i
>> cannot listen to headphones plugged into my hdmi monitor.  (Under
>> ubuntu 15.10 i could do this, so i know it is not a hardware problem.)
>>
>> Now, unfortunately, i'm far too ignorant to have any ideas about your
>> question "with modern lcd monitors is there any difference between
>> sleep and a software shut off?"
>>
>> But i think it would be useful to know in order to construct some
>> sort
>> of model of how hdmi works (what states can a monitor be in, and what
>> transitions are possible under what conditions between the states).
>>
>> Anyhow, thanks again for your help!  (And thanks everybody else also.
>> I've learned something from every suggestion.)
>>
>> dan
>>
>>
>> On Sun, May 8, 2016 at 11:32 AM, Victor Forberger
>> <vforberger at fastmail.fm> wrote:
>>>
>>>  On 05/08/2016 11:52 AM, Dan Hitt wrote:
>>>>
>>>>  On Sun, May 8, 2016 at 5:07 AM, Petter Adsen <petter at synth.no> wrote:
>>>>>
>>>>>  On Sat, 7 May 2016 20:32:03 -0700
>>>>>  Dan Hitt <dan.hitt at gmail.com> wrote:
>>>>
>>>>  .....
>>>>>>
>>>>>>  Occasionally after i lock the screen and come back after a few hours
>>>>>> i
>>>>>>  cannot get it to respond.
>>>>>>
>>>>>>  The machine is alive, and i can ssh into from another host.
>>>>>>
>>>>>>  But wiggling the mouse and pressing keys leaves the monitor pitch
>>>>>>  black.
>>>>
>>>>  .....
>>>>>
>>>>>
>>>>>  If you don't mind restarting your entire X session, you can try 'sudo
>>>>>  systemctl restart lightdm.service'. You could also try to kill the
>>>>>  screen locker process, I think Xfce uses light locker by default.
>>>>
>>>>
>>>>
>>>>  Thanks Petter!
>>>>
>>>>  So the problem came up again
>>>> after i last wrote (i had to go do some
>>>>  chores, and when i came back keyboarding and mousing did not bring
>>>>  back the display).
>>>>
>>>>  So i tried your suggestion of restarting lightdm.
>>>>
>>>>  And it worked, so thanks!
>>>>
>>>>  I did lose my X state, but i don't think any other state.
>>>>
>>>>  This seems to indicate that lightdm is going into too deep a sleep, or
>>>>  perhaps taking something to sleep with it that should stay awake.
>>>>
>>>>  If anybody has any advice about how to approach this kind of lightdm
>>>>  problem, i'm all ears --- although i know next-to-nothing about
>>>>  lightdm.
>>>>
>>>>  Thanks again everybody for all the suggestions.  They were all helpful.
>>>>
>>>>  dan
>>>
>>>
>>>  I had a similar problem a ways back. I'm sorry if I can't pull up
>>>  specific info from my past problem-solving (I searched through various
>>>  logs in /var/log for log entries that identified what the problem was).
>>>
>>>  But, I do recall
>>> the problem was actually related to the monitor being
>>>  shut off (as opposed to just dimmed). When unlocking the computer for
>>>  use after a long delay, the process for turning the monitor back on was
>>>  not working. I fixed the problem by changing power manager settings so
>>>  that the display was never turned off, only put to sleep. Once that
>>>  setting was changed, lightlocker could activate the monitor again once
>>>  the session was unlocked.
>>>
>>>  Restarting lightdm certainly will also do the trick. But, it is a
>>>  radical solution, especially if the problem is just related to getting
>>>  the monitor to connect to the xfce window manager (note that xfce runs
>>>  on top of lightdm -- i.e., lightdm provides the login screen when the
>>>  computer is turned on; xfce is the actual desktop environment for
>>>  getting work done after a successful login).
>>>
>>>  And, one question here: with modern lcd monitors is there any difference
>>>  between
>>> sleep and a software shut off?
>>>
>>>  - Victor
>>>
>>>  --
>>>  Victor Forberger
>>>  vforberger at fastmail.fm
>>>  blog: http://linuxatty.wordpress.com
>>>
>>>
>>>
>>>  --
>>>  xubuntu-users mailing list
>>>  xubuntu-users at lists.ubuntu.com
>>>  Modify settings or unsubscribe at:
>>> https://lists.ubuntu.com/mailman/listinfo/xubuntu-users
>>
>>
>
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