From: spamtrap42@jacob21819.net   
      
   Each of my /var/log/syslog and /var/log/kern.log is over 1GB   
   today after unplugging two monitors and plugging in two different   
   monitors.   
      
   The hardware is about 5 years old:   
     - Motherboard: Asus Pro WS X570-ACE   
     - Processor: AMD Ryzen 7 5800X 8-Core Processor   
     - GPU: MSI Radeon RX5500XT   
     - old monitors: 2x Asus VW266H   
     - new monitors: 2x Asus PA279CV   
      
   Software is Devuan Daedalus.   
      
   The old monitors were connected to the first two DisplayPort   
   connectors via (probably no-name) DisplayPort-to-HDMI adapters   
   and a Kopul HDMI switchers.   
      
   The new monitors are connected to the same first two DisplayPort   
   connectors via PearStone DisplayPort-to-HDMI adapters and the   
   same Kopul HDMI switchers.   
      
   (The switchers let me push a button and see security camera   
   output on one monitor, then push another button to go back to   
   computer stuff.)   
      
   I had tested the new monitors and adapter cables via the GPU's   
   third DisplayPort connector, with and without going through the   
   switcher.  All tested out well.   
      
   Today, while the machine would have been showing the text console   
   and not X, I physically installed the new monitors on the   
   above-desk mounts and plugging everything in.  The switchers   
   showed that there was signal on the input line, but the monitors   
   stayed in standby mode.  About the time I plugging things in,   
   syslog and kern.log show the following:   
      
   2026-01-12T12:00:37.370890-08:00 one kernel: [180281.980042] [dr   
   :retrieve_link_   
   cap [amdgpu]] *ERROR* retrieve_link_cap: Read receiver caps dpcd data failed.   
   2026-01-12T12:00:38.627964-08:00 one kernel: [180283.233347] ------------[ cut   
   h   
   ere ]------------   
   2026-01-12T12:00:38.627976-08:00 one kernel: [180283.234095] WARNING: CPU: 7   
   PID   
   : 13497 at drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:3076   
   dc_update_pla   
   nes_and_stream+0x342/0x880 [amdgpu]   
      
   then lists of kernel modules, register dumps, stack traces   
   and etc.   
      
   then a ton of these:   
      
   2026-01-12T12:00:38.754724-08:00 one kernel: [180283.364640] [dr   
   :dc_add_plane_to_context [amdgpu]] *ERROR* Head pipe not found for   
   stream_state 000000000268a75b !   
   2026-01-12T12:00:38.758717-08:00 one kernel: [180283.365909] [dr   
   :dc_add_plane_to_context [amdgpu]] *ERROR* Head pipe not found for   
   stream_state 000000000268a75b !   
   2026-01-12T12:00:38.758720-08:00 one kernel: [180283.367165] [dr   
   :dc_add_plane_to_context [amdgpu]] *ERROR* Head pipe not found for   
   stream_state 000000000268a75b !   
      
   at a rate of about 980 per second for a total of about 6,803,402   
   lines and just over 1GB of text in each file.  Thankfully, a   
   clean reboot of the machine accomplished via a thin-client   
   machine, the GPU, switchers, and monitors signed a peace treaty   
   and are now happily working together.   
      
   Has anyone else seen anything similar to that?   
      
   Thanks.   
      
   --   
   Robert Riches   
   spamtrap42@jacob21819.net   
   (Yes, that is one of my email addresses.)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)