[lubuntu] Screen Resolution Not Autodetected

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JMac87
Posts: 3
Joined: Tue Apr 18, 2017 7:45 pm

[lubuntu] Screen Resolution Not Autodetected

Postby JMac87 » Tue Apr 18, 2017 7:53 pm

Posting this here because the ubuntuforums Lubuntu section seems a bit dead.

This is a bit of a strange issue. I built two identical machines with the following embedded board: http://www.asrock.com/mb/Intel/J4205-ITX/index.us.asp

I installed Lubuntu 16.10 on both. When I plugged the first machine into a 1080p LED Sharp TV using an HDMI cable, it autodetected 1920x1080 as the max resolution. Great! Keep in mind I didn't have to install any additional Intel graphics drivers. For the second machine, I plugged it into a Samsung 4K TV using an HDMI cable. When it boots, it lists 1024x768 as the maximum resolution. Huh?

I installed and uninstalled the usual xserver-xorg-video-intel package, I've also installed the Intel driver update tool from: https://01.org/linuxgraphics/downloads/update-tool

No dice.

The only way I can get to a higher resolution is to do the following:

Code: Select all

cvt 1920 1080 60
xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
xrandr --addmode DP-1 1920x1080_60.00


That will add 1920x1080 to the Screen Resolution app and then I can select it and all is well, until I reboot of course.

I've tried adding 3840x2160 as well, but it doesn't do anything....it just stays at 1920x1080. Of course, if I reboot, these settings don't stick as expected. I've tried adding the modes to /usr/share/X11/xorg.conf.d/10-monitor.conf, but then my system doesn't boot past the fsck.

What gives?

seppalta
Posts: 363
Joined: Tue Sep 20, 2011 6:09 am
Location: USA
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Re: [lubuntu] Screen Resolution Not Autodetected

Postby seppalta » Wed Apr 19, 2017 2:02 am

Just add your code to your autostart file.

JMac87
Posts: 3
Joined: Tue Apr 18, 2017 7:45 pm

Re: [lubuntu] Screen Resolution Not Autodetected

Postby JMac87 » Wed Apr 19, 2017 2:13 pm

seppalta wrote:Just add your code to your autostart file.

Sure, I can do that.... But it doesn't explain why the resolution isn't being autodetected. Also, 4k does not work at all...it just stays at 1920x1080.

seppalta
Posts: 363
Joined: Tue Sep 20, 2011 6:09 am
Location: USA
Contact:

Re: [lubuntu] Screen Resolution Not Autodetected

Postby seppalta » Thu Apr 20, 2017 1:10 am

Big screens with the super high resolutions you are wanting are a relatively new thing. Is it suppose to be able to detect them?

JMac87
Posts: 3
Joined: Tue Apr 18, 2017 7:45 pm

Re: [lubuntu] Screen Resolution Not Autodetected

Postby JMac87 » Thu Apr 20, 2017 5:21 pm

seppalta wrote:Big screens with the super high resolutions you are wanting are a relatively new thing. Is it suppose to be able to detect them?

Well, let's take out 4K for the moment then. It's still not auto-detecting 1920x1080.

An exact identical build is autodetecting a 1920x1080 TV without issue.

rufwoof
Posts: 10
Joined: Thu Sep 15, 2016 10:49 am

Re: [lubuntu] Screen Resolution Not Autodetected

Postby rufwoof » Fri Apr 21, 2017 11:48 pm

After you run Preferences/Monitor Settings it records that in
~/.config/autostart/LXRandR autostart.desktop
Mine looks like

Code: Select all

[Desktop Entry]
Type=Application
Name=LXRandR autostart
Comment=Start xrandr with settings done in LXRandR
Exec=sh -c 'xrandr --output DVI-I-2 --mode 1280x768 --output DVI-I-1 --off'
OnlyShowIn=LXDE

Surely auto-detection is more a function of the kernel/op-sys rather than LXDE i.e. Lubuntu?


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