RHEL6 hangs on message "ACPI: EC: Look up EC in DSDT" during boot

Issue

Kernel hangs during boot with the last message: "ACPI: EC: Look up EC in DSDT". It might happen as a new install or after upgrade.

For example, last messages could be:

...
regulator: core version 0.5
NET: Registered protocol family 16
ACPI FADT declares the system doesn't support PCIe ASPM, so disable it
ACPI: bus type pci registered
PCI: MCFG configuration 0: base f8000000 segment 0 buses 0 - 63
PCI: MCFG area at f8000000 reserved in E820
PCI: Using MMCONFIG for extended config space
PCI: Using configuration type 1 for base access
bio: create slab <bio-0> at 0
ACPI: EC: Look up EC in DSDT