Further debugging today while I'm on-site with the kiosks. The system froze, as usual, after normal idle screen blanking. I was able to login via ssh and retrieve some details.
First, it appears that the basic screen blanking problem is somehow related to the Radeon driver. I will attach the Xorg.0.log file and a gdb backtrace on the running but non-responsive Xorg process. No keyboard or mouse activity will un-blank the screen. Here's the output from lspci | grep VGA: 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV516 [Radeon X1300/X1550 Series] I'll also attach the PCI ROM dump from the /sys/devices rom file for this device. This suggests that when we use Alt-SysRq-k to restore the system, sometimes we trigger *another* bug in the driver which results in the overall system crash. See the attached apr1.full.kern.log file for what details I could recover from the crash on April 1st; that corresponds to the screen photo I took that day (the radeon_kernel_panic1.jpg attachment). The Xorg "hang" bug which precedes this appears similar, but not identical, to what is documented in #1664979: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1664979 I will continue to try to study the live Xorg process to see if I can determine where its hung, but I may not have time this evening. Let me know if there are specific further debugging steps I can take to examine either the Xorg hang or the subsequent crash which (sometimes) follows on attempting to recover with Alt-SysRq-k. (And note that I'll copy in the files apport-bug generated from #1764211 later tonight, using my "cdarroch" personal account, and then I'll try to close that extra bug report.) Thanks very much, Chris. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1763273 Title: kernel panic in Radeon driver while screen blank To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1763273/+subscriptions -- ubuntu-bugs mailing list firstname.lastname@example.org https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs