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?