[Note: this is similar to issue #418 in the gnome gitlab but it happens to me constantly and I'm not running Evolution. I filed this there too, but gnome 3.28.2 is no longer supported there.]
I'm not sure how long this has been going on or what triggered it, but I recently noticed that my syslog is being spammed with the same 3 lines repeatedly. For example:
$ tail -f /var/log/syslog
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): EDID vendor "APP", prod id 41006
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Printing DDC gathered Modelines:
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Modeline "2880x1800"x0.0 337.75 2880 2928 2960 3040 1800 1803 1809 1852 +hsync -vsync (111.1 kHz eP)
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): EDID vendor "APP", prod id 41006
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Printing DDC gathered Modelines:
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Modeline "2880x1800"x0.0 337.75 2880 2928 2960 3040 1800 1803 1809 1852 +hsync -vsync (111.1 kHz eP)
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): EDID vendor "APP", prod id 41006
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Printing DDC gathered Modelines:
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Modeline "2880x1800"x0.0 337.75 2880 2928 2960 3040 1800 1803 1809 1852 +hsync -vsync (111.1 kHz eP)
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): EDID vendor "APP", prod id 41006
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Printing DDC gathered Modelines:
Jul 10 04:35:53 496-MBP /usr/lib/gdm3/gdm-x-session[2094]: (II) RADEON(0): Modeline "2880x1800"x0.0 337.75 2880 2928 2960 3040 1800 1803 1809 1852 +hsync -vsync (111.1 kHz eP)
etc. (at least 8 times per second)
I'm trying to figure out (and fix) what's causing this. I'd appreciate any tips/pointers as to how to diagnose this.
I'm running Ubuntu on an older (2015-ish) MacBook Pro with Gnome 3.28.2 (and all apt-installed sw up-to-date):
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.4 LTS
Release: 18.04
Codename: bionic
$ apt-cache policy gdm3
gdm3:
Installed: 3.28.3-0ubuntu18.04.4
Candidate: 3.28.3-0ubuntu18.04.4
Version table:
*** 3.28.3-0ubuntu18.04.4 500
500 http://ca.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
100 /var/lib/dpkg/status
3.28.0-0ubuntu1 500
500 http://ca.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
$ apt-cache policy xserver-xorg
xserver-xorg:
Installed: (none)
Candidate: 1:7.7+19ubuntu7.1
Version table:
1:7.7+19ubuntu7.1 500
500 http://ca.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
1:7.7+19ubuntu7 500
500 http://ca.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
$ uname -a
Linux 496-MBP 5.3.0-62-generic #56~18.04.1-Ubuntu SMP Wed Jun 24 16:17:03 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
$ inxi
CPU~Quad core Intel Core i7-4980HQ (-MT-MCP-) speed/max~798/4000 MHz Kernel~5.3.0-62-generic x86_64 Up~51 min Mem~2430.2/15889.5MB HDD~1000.6GB(35.4% used) Procs~337 Client~Shell inxi~2.3.56
$ xrandr
Screen 0: minimum 320 x 200, current 2880 x 1800, maximum 16384 x 16384
eDP connected primary 2880x1800+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
2880x1800 59.99*+
1920x1200 59.95
1920x1080 60.00
1600x1200 59.95
1680x1050 60.00
1400x1050 60.00
1280x1024 59.95
1440x900 59.99
1280x960 59.99
1280x854 59.95
1280x800 59.96
1280x720 59.97
1152x768 59.95
1024x768 59.95
800x600 59.96
848x480 59.94
720x480 59.94
640x480 59.94
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 disconnected (normal left inverted right x axis y axis)
$ lspci -nn | grep -E 'VGA|Display'
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Venus XT [Radeon HD 8870M / R9 M270X/M370X] [1002:6821] (rev 83)
Please let me know if there's other information that could help with a diagnosis.
Thanks!