BAT1: Unable to dock after suspend to RAM

[Bill Sun <cap.sensitive@xxxxxxxxx>]

Hi,

I noticed there's alway an 'Unable to dock' error message after suspend
to RAM:
    PM: Saving platform NVS memory
    Disabling non-boot CPUs ...
    smpboot: CPU 1 is now offline
    smpboot: CPU 2 is now offline
    smpboot: CPU 3 is now offline
    Extended CMOS year: 2000
    ACPI: Low-level resume complete
    PM: Restoring platform NVS memory
    Extended CMOS year: 2000
    Enabling non-boot CPUs ...
    smpboot: Booting Node 0 Processor 1 APIC 0x1
    Disabled fast string operations
    CPU1 is up
    smpboot: Booting Node 0 Processor 2 APIC 0x2
    Disabled fast string operations
    CPU2 is up
    smpboot: Booting Node 0 Processor 3 APIC 0x3
    Disabled fast string operations
    CPU3 is up
    ACPI: Waking up from system sleep state S3
    ACPI: \_SB_.PCI0.LPC_.EC__.BAT1: docking
    ACPI: \_SB_.PCI0.LPC_.EC__.BAT1: Unable to dock!

System info:
ThinkPad X220, Linux 3.8.6 (ARCH), systemd 201-1, 1.4.1-5

I have tried to set Handle{SuspendKey,HibernateKey,LidSwitch} all to
ignore, but I still get the same error message. Any other solution to
make that message disappear?

Regards.