Hi, everyone.

tldr: How in the heck do I force CentOS7 to boot to a low/conservative GDM
resolution?

Hoping someone can lend a hand getting CentOS7 to sync to my Panasonic Vierra 42′ TV. It worked fine in CentOS6.5 but since installing I boot to a GDM background with no login prompt. I can SSH into the node and configure multiuser runlevel but that’s not fun at all. ;)

Here’s the output of xrandr:

# systemctl get-default graphical.target

# xrandr -display \:0 -q Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 connected primary 1920×1080+0+0 (normal left inverted right x axis y axis) 698mm x 392mm
1920×1080 60.0* 59.9 24.0 24.0
1920x1080i 60.1 60.0
1280×720 60.0 59.9
1440x480i 60.1 60.1 60.1
720×480 60.0 59.9
640×480 60.0 59.9
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)

# xrandr -display \:0 –output HDMI1 –mode 640×480
# echo $?
0

# /bin/systemctl restart gdm.service
# echo $?
0

So setting to something very conservative doesn’t make a difference nor do any of the other detected modes. I also tried bouncing the TV to see if that would help. Nada.