[CentOS] Laptop display issue

Fri Oct 2 16:24:06 UTC 2020
H <agents at meddatainc.com>

On October 1, 2020 3:42:34 PM EDT, H <agents at meddatainc.com> wrote:
>I now have an older laptop with a display problem. I installed Centos 7
>on it in February and had to install the xorg-x11-drv-ati and evdev
>drivers because the docking station has an ATI Radeon card. Everything
>worked fine with a dual display setup. I probably after that ran a
>system update but did not reboot while in this office. Today, when I
>got to the office again for the first time in seven months it does not
>boot into the desktop but fails after displaying ”Started Light Display
>Manager” with a mouse pointer on one display that can be moved but no
>desktop at all. The keyboard works and I can start a terminal session.
>If I remove the laptop from the docking station everything works as
>expected but not in the station, presumably because it now uses the
>docking station card. Futzing around I see that systemctl --failed
>lists nothing, nor did dmesg immediately suggest a reason. In the yum
>history I see that this driver was updated to 19.0.1-3 from the
>19.0.1-2 that installed with. Yum downgrade to 19.0.1-2 did not change
>the issue. Nor has booting an older kernel helped so far.
>Although when I remove quiet from the grub command line it seems to
>stop after ”Started Load CPU microcode update” following the ”Started
>Light Display Manager” already mentioned, I strongly suspect some issue
>with the graphics driver.
>Since the computer boots and seems to run fine with the internal
>display when removed from the docking station it seems that there are
>no hardware issues in the unit itself. My understanding is that the ATI
>driver can be a problem and needs to match the kernel etc - perhaps
>there is something wrong here?
>Any suggestions for how to attack this? I need to use it in the docking
>station and have no alternative. Thank you.

Researching this further, the issue seems to be with x11. I found that blindly typing my password to log into the system seems to log me in and launches the expected startup applications. Since there is no desktop on the display, I can start a CtrlAlt-F2 root session and can verify this by ps aux.

Looking at Xorg.0.log, I see an error message - when I do not log in as a regular user - ”failed to add fb -22” followed by ”modeset(0): failed to set mode: invalid argument”. This is presumably the point of failure in displaying the graphical desktop.

Again, this is a ATI Radeon card and occurred after ”some” yum update. I have not been able to revert to a previous working desktop yet, loading an older kernel does not help. I suspect it is some interaction between the kernel, the display driver and x11.

I found that after initially installing the x11 ATI driver I had also installed fglrx-x11 from elrepo I believe but can now not find it, nor whether there is an update available that might resolve my problem.

Any suggestions?