Kernel 4.1.4 breaks external display

CS DBA cs_dba at consistentstate.com
Fri Sep 4 16:08:25 UTC 2015



On 09/02/2015 08:00 PM, Ed Greshko wrote:
> On 09/03/15 09:06, CS DBA wrote:
>> On 08/31/2015 08:34 PM, Ed Greshko wrote:
>>> On 08/21/15 23:41, CS DBA wrote:
>>>> I'm running Fedora 21 on a Dell M3800 laptop, been working great.
>>>> Updating to the latest kernel however breaks my external display
>>>> i.e. I plug the external monitor in and nothing happens, previous to the
>>>> update when I plug in the external monitor
>>>> the system would auto configure the second screen and I could use both
>>>> monitors.
>>>>
>>>> I've googled the issue but not found anything.
>>>>
>>>> Thoughts?
>>> Several thoughts come to mind...
>>>
>>> 1.  What desktop are you using?  GNOME. KDE, xfce, something else
>> KDE
>>
>>> 2.  Did you try going back to a working kernel?
>> Yes, I had an rsync of the system from before the updae, running now
>> with kernel 4.0.8-200 and it works
>>
>>
>>> 3.  It seems as if you're saying you've booted without the monitor attached and plug it in later?  Yes?  If so, have you tried booting with the monitor already attached?   Or, attaching the monitor and then logging out/in?
>> I've tried all of the above with the updated kernel, no luck. The second
>> screen remains blank and I cannot move the mouse past the edge of the
>> laptop screen irrespective of if I boot / login with the monitor
>> attached or not
> OK.... 
>
> I think I see what is happening as I ran into this a while back myself and just tested it on an Acer Laptop running F22/KDE
>
> Bring up "System Settings" and go to "Hardware--->Display and Monitior-->Display Configuration".   Assuming you see both monitors, make sure they are aligned as they are physically.  Position them and hit apply.
>
> Then move your mouse to the "blank" monitor.  If it is want I think it is, the arrow pointer will "disappear".  Then right click and with any luck a dialog box will appear and you'll be able to select either "Desktop" or "Folder View" settings an pick a background.  Initially, I found that the background is "black" and it just looks like the display is not working.

No dice, the display section of the system settings only shows the
laptop screen



>
>
>



More information about the users mailing list