FreeBSD 11.1, Xfce, and laptop screen and external monitor resolution

David Christensen dpchrist at
Wed Aug 2 04:48:50 UTC 2017

On 07/30/17 21:18, Polytropon wrote:
> On Sun, 30 Jul 2017 19:30:01 -0700, David Christensen wrote:
>> When I run 'startxfce4', Xfce starts with a resolution of 1024x768.
>> Applications Menu -> Settings -> Display offers two choices: 1024x768
>> and 800x600.  How do I set the Xfce resolution to 1280x800 when driving
>> the laptop screen?
> Option 1 is to set it using a configuration file "snippet" in the
> /usr/local/etc/X11/xorg.conf.d directory,
> xorg.conf: only put section "Screen", subsection "Display",
> setting "Modes" with the screen size you want.
> For example, it could look like this:
> 	Section "Screen"
> 		Identifier	"Screen0"
> 		Device		"Card0"
> 		Monitor		"Monitor0"
> 		DefaultDepth	24
> 	        SubSection "Display"
> 			Viewport	0 0
> 			Depth		24
> 			Visual		"TrueColor"
> 			Modes           "1920x1080" "1280x800"
> 	        EndSubSection
> 	EndSection

The driver is supposed to read the EDID information for all 
available displays and act upon it "correctly"; this is not happening.

I did some testing using FreeBSD 11.0 -- EDID works.  But if I attempt 
to run in dual-head mode, I get the same bug as FreeBSD 11.1 where 
windows and dialogs are mostly blacked out.

So, there are several bugs at work here.  If/when I have the time and 
inclination, I will try to tease them out one at a time and file bug 

> You could then probably even use Ctrl+Alt+[+] and Ctrl+Alt+[-]
> to switch between the two modes (not tested, but old-fashioned
> X could do that).

Yes, I'm finding that I need old-school tricks.

> Option 2 is to use xrandr in ~/.xinitrc with the --size
> option.

This is 2017 and I shouldn't have to mess with low-level X stuff.  This 
is just more infinite bug propagation, as I lamented on the TrueOS forum:

>> If I connect an external 1920x1080 monitor to the VGA port of the laptop
>> and press the Fn+F8 (CRT/LCD) hot key at the GELI prompt, the video
>> signal is sent to the external monitor (laptop screen goes dark).  (I
>> then close the laptop screen.)  'startxfce4' results in Xfce with a
>> resolution of 1600x1200.  Display offers choices of 1600x1200,
>> 1280x1024, 1024x768, 800x600, and 640x480.  How do I set the Xfce
>> resolution to 1920x1080 when driving the external monitor?
> Similar to the approach for the laptop's screen. You can even
> use xrandr from inside a running X session to change the screen
> size dynamically. It's also a convenient tool for experiments.
> (Side note: I set up a Dell Latitude D630 laptop with a screen
> size of 1280x800 and an external monitor of 1920x1080, but I
> use Mate on this specific system which offers the native screen
> size in its configuration program.)

As above.


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