ACPI Exception: AE_NOT_FOUND, while evaluating GPE method - floods syslog

Question

On my new desktop, after waking up from sleep one of my CPUs is constantly on 100% use, initially it was the xorg process (4289), now its the kworker thread.

My /var/log/syslog is flooded (850+ lines / second) with this messages:

Aug 26 17:10:55 mortal kernel: [ 3657.482759] ACPI Error: [PGRT] Namespace lookup failure, AE_NOT_FOUND (20160108/psargs-359)
Aug 26 17:10:55 mortal kernel: [ 3657.482760] ACPI Error: Method parse/execution failed [\_GPE._L6F] (Node ffff8810348d56e0), AE_NOT_FOUND (20160108/psparse-542)

Output of top

   88 root      20   0       0      0      0 D  94,0  0,0  28:32.44 [kworker/0:1]                                                                                              
 4289 root      20   0  418620 164880  68252 S  15,6  0,3   4:27.62 /usr/lib/xorg/Xorg :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch             
 3404 root      20   0  258320   3540   1948 S  10,3  0,0   5:31.55 /usr/sbin/rsyslogd                                                                                         
 5175 mor       20   0 1348768  63636  46232 S   5,3  0,1   1:34.50 vlc                                                                                                        
 4497 mor       20   0  486068  33220  25884 S   5,0  0,1   0:17.19 marco                                                                                                      
 4531 mor       20   0  482184  27524  20684 S   4,0  0,0   0:15.24 /usr/lib/mate-panel/wnck-applet                                                                            
 4709 mor       20   0 1708964 435576 123388 S   4,0  0,7   7:23.20 firefox-esr                                                                                                
 4291 root      20   0  273140   5864   4984 S   3,0  0,0   1:35.58 /usr/lib/accountsservice/accounts-daemon                                                                   
 4517 mor        9 -11  574288  12692   9456 S   1,7  0,0   1:07.14 /usr/bin/pulseaudio --start --log-target=syslog                                                            
 4667 mor       20   0  261672  22152  18844 S   0,7  0,0   0:31.10 gkrellm                                                                                                    
    7 root      20   0       0      0      0 S   0,3  0,0   0:04.67 [rcu_sched]                                                                                                
 1134 root      20   0       0      0      0 S   0,3  0,0   0:00.29 [jbd2/sda2-8]                                                                                              
 4432 mor       20   0  406236  26144  20616 S   0,3  0,0   0:00.31 x-session-manager                                                                                          
 4493 mor       20   0 1459196  32440  25336 S   0,3  0,0   0:03.45 /usr/bin/mate-settings-daemon                                                                              
 4501 mor       20   0  565268  34848  26120 S   0,3  0,1   0:03.35 mate-panel                                                                                                 
 4513 mor       20   0 1242952  44264  35320 S   0,3  0,1   0:02.10 caja                                                                                                       
 4543 mor       20   0  526044  34764  28612 S   0,3  0,1   0:01.08 mate-screensaver                                                                                           
 4618 mor       20   0  548024  29876  23360 S   0,3  0,0   0:00.35 /usr/lib/mate-panel/clock-applet                                                                           
 5541 mor       20   0   81856  12128   5672 S   0,3  0,0   0:00.81 xterm                                                                                                      
 6090 mor       20   0  389372  48044  37352 S   0,3  0,1   0:00.86 keepassx                                                                                                   
 6291 mor       20   0   42928   3776   3008 R   0,3  0,0   0:00.83 top                                                                                                        
 6300 mor       20   0   86828  16924   5720 S   0,3  0,0   0:01.08 xterm                                                                                                      
    1 root      20   0   15820   1800   1632 S   0,0  0,0   0:01.13 init [2]                                                                                                   
    2 root      20   0       0      0      0 S   0,0  0,0   0:00.00 [kthreadd]                                                                                                 
    3 root      20   0       0      0      0 S   0,0  0,0   0:00.03 [ksoftirqd/0]                                                                                              
    5 root       0 -20       0      0      0 S   0,0  0,0   0:00.00 [kworker/0:0H]                                                                                             
    8 root      20   0       0      0      0 S   0,0  0,0   0:00.00 [rcu_bh]                                                                                                   
    9 root      rt   0       0      0      0 S   0,0  0,0   0:00.02 [migration/0]                                                                                              
   10 root      rt   0       0      0      0 S   0,0  0,0   0:00.00 [watchdog/0]                                                                                               
   11 root      20   0       0      0      0 S   0,0  0,0   0:00.00 [cpuhp/0]                                                                                                  
   12 root      20   0       0      0      0 S   0,0  0,0   0:00.00 [cpuhp/1]                                                                                                  
   13 root      rt   0       0      0      0 S   0,0  0,0   0:00.03 [watchdog/1]                                                                                               
   14 root      rt   0       0      0      0 S   0,0  0,0   0:00.01 [migration/1]                                                                                              
   15 root      20   0       0      0      0 S   0,0  0,0   0:00.00 [ksoftirqd/1]                                                                                              
   16 root      20   0       0      0      0 S   0,0  0,0   0:00.00 [kworker/1:0]                                                                                              

What could be the cause of this, and how could I debug it?

Answer 1

This is a known bug in the linux kernel with the Skylake chipset.

I've found a work around here, that causes the symptoms to go away.

Issue this command (as root, add 'sudo' in case you are not root):

echo "disable" > /sys/firmware/acpi/interrupts/gpe6F

This will disable the offending ACPI Interrupt until the next boot. If this happens often to you and BIOS and Kernel Updates did not remove it, file a new bug report on the kernel bugzilla.

Its reported (Comment #20) to work with BIOS version 2.00 on Asrock H170 Pro4S. Tested with kernels 4.5 and 4.6.

Addendum Since I upgraded my BIOS Firmware recently I never got the problem. But upgrading has nearly bricked my machine and it took a while to recover, so weigh that in your decision to do that.

Answer 2

You're now able to add a parameter to your kernel at boot to prevent this from happening. Just add acpi_mask_gpe=0x6f to your kernel boot parameters.

This is going to be different depending on your bootloader. For instance, I'm using grub (and Arch), so I had to add it to the /etc/default/grub file and rebuild it with grub-mkconfig -o /boot/grub/grub.cfg. Here's some instructions on Arch's wiki, but YMMV: https://wiki.archlinux.org/index.php/kernel_parameters

Here's the bug comment that states the fix, https://bugzilla.kernel.org/show_bug.cgi?id=117481#c23, and that contains a link to the actual patch.