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These are the warnings when I run dmesg.

ACPI: Deleted _OSI(Windows 2012)
ACPI: Deleted _OSI(Windows 2013)
ACPI: RSDP 00000000000f0410 00024 (v02 INTEL )
ACPI: XSDT 00000000bdfaad98 000B4 (v01 INTEL    ROMLEY 06222004 INTL 20090903)
ACPI: FACP 00000000bdfaa918 000F4 (v04 INTEL    ROMLEY 06222004 INTL 20090903)
**ACPI Warning: Invalid length for Pm1aControlBlock: 32,** using default 16 (20090903/tbfadt-615)
ACPI: DSDT 00000000bdf8f018 19656 (v02 INTEL    ROMLEY 00000002 INTL 20100331)

And in bios there is no acpi setting to disable so I try acpi=off in grub.conf file but after that no acpi logs are coming. What should I do to remove the acpi warning?

marked as duplicate by n.st, Thomas, GAD3R, thrig, G-Man Nov 26 '18 at 7:52

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According to RHEL documentation:

This message is informational only. It does not indicate anything is wrong and can be safely ignored.

Root Cause

The system hardware defines a 32-bit register size for its ACPI Pm1aControlBlock and Pm2ControlBlock, however the ACPI specification defines a 16-bit register size for the Pm1aControlBlock and 8-bit register size for Pm2ControlBlock.

This message is telling you that the kernel's ACPI code is ignoring the hardware register size, and using the ACPI specification size.

  • It's good netiquette to link back to the sources you used; I've done that here for you. – Jeff Schaller Nov 25 '18 at 22:05

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