What are 'dmesg' failure messages?

Question

When I'm executing the dmesg command on my RHEL 7.4 server, I'm noticing following failure messages:

[root@localhost ~]# dmesg | grep -i fail
[    0.984930] acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM
[    0.990907] acpi PNP0A03:01: _OSC failed (AE_NOT_FOUND); disabling ASPM
[    1.058883] pci 0000:7f:12.4: BAR 2: failed to assign [mem size 0x00000040]
[    1.058889] pci 0000:7f:12.4: BAR 4: failed to assign [mem size 0x00000040]
[    1.058894] pci 0000:7f:12.4: BAR 1: failed to assign [mem size 0x00000010]
[    1.058899] pci 0000:7f:12.4: BAR 3: failed to assign [mem size 0x00000010]
[    1.058904] pci 0000:7f:12.4: BAR 5: failed to assign [mem size 0x00000010]
[    1.058910] pci 0000:7f:12.0: BAR 6: failed to assign [mem size 0x00000001 pref]
[    1.058915] pci 0000:7f:1e.3: BAR 6: failed to assign [mem size 0x00000001 pref]
[    1.058943] pci 0000:ff:12.4: BAR 2: failed to assign [mem size 0x00000040]
[    1.058948] pci 0000:ff:12.4: BAR 4: failed to assign [mem size 0x00000040]
[    1.058953] pci 0000:ff:12.4: BAR 1: failed to assign [mem size 0x00000010]
[    1.058958] pci 0000:ff:12.4: BAR 3: failed to assign [mem size 0x00000010]
[    1.058963] pci 0000:ff:12.4: BAR 5: failed to assign [mem size 0x00000010]
[    1.058969] pci 0000:ff:12.0: BAR 6: failed to assign [mem size 0x00000001 pref]
[    1.058974] pci 0000:ff:1e.3: BAR 6: failed to assign [mem size 0x00000001 pref]
[    1.059093] pci 0000:02:00.1: BAR 6: failed to assign [mem size 0x00080000 pref]
[    1.059099] pci 0000:02:00.2: BAR 6: failed to assign [mem size 0x00080000 pref]
[    1.059105] pci 0000:02:00.3: BAR 6: failed to assign [mem size 0x00080000 pref]
[    4.279113] be2net 0000:81:00.0: opcode 80-1 failed:status 1-23
[    4.530130] be2net 0000:81:00.1: opcode 80-1 failed:status 1-23
[    4.729139] be2net 0000:81:00.2: opcode 80-1 failed:status 1-23
[    4.928150] be2net 0000:81:00.3: opcode 80-1 failed:status 1-23

What do these three error messages mean?

• acpi PNP0A03:XX: _OSC failed (AE_NOT_FOUND); disabling ASPM
• pci 0000:XX:XX.X: BAR X: failed to assign [mem size 0x00000040]
• be2net 0000:81:00.X: opcode 80-1 failed:status 1-23

Note: be2net is ethernet driver for HPE FlexFabric 20Gb 2-port 650FLB Adapter.

Answer 1

Trying to diagnose problems on dmesg or syslog using grep is a bad idea, because you are throwing away all the context (previous lines, following lines) that will allow you to identify what is actually going on (or at least more about what is going on).

From the information you have given:

ACPI information is used on boot to initialize devices. PNP0A03 is the plug'n'play information for the PCI bus, _OSC is some ACPI method used to initialize it. That method failed to execute for whatever reason, so Linux deciced to disable Active State Power Management (ASPM).

Possibly as a consequence of that, some PCI devices with a really weird bus number (ff and 7f) didn't initialize properly, very likely because they had bogus memory region ("BAR") information.

Diagnosis: Something is wrong with your PCI host controller, or it is not properly initialized because the BIOS ACPI information is wrong. Compare with the lspci output you have, and any information about malfunctioning PCI cards. Look at the complete dmesg boot log.

The be2net error can really be anything: A harmless error because some opcode the driver tried isn't supported by your hardware, a bug in the driver, a consequence of the bad PCI host controller, or ...