Allow supported ACPI revision to be overridden
configname: CONFIG_ACPI_REV_OVERRIDE_POSSIBLE
Linux Kernel Configuration
└─>Power management and ACPI options
└─>ACPI (Advanced Configuration and Power Interface) Support
└─>Allow supported ACPI revision to be overridden
In linux kernel since version 4.2 (release Date: 2015-08-30)
The platform firmware on some systems expects Linux to return "5" as
the supported ACPI revision which makes it expose system configuration
information in a special way.
For example, based on what ACPI exports as the supported revision,
Dell XPS 13 (2015) configures its audio device to either work in HDA
mode or in I2S mode, where the former is supposed to be used on Linux
until the latter is fully supported (in the kernel as well as in user
space).
This option enables a DMI-based quirk for the above Dell machine (so
that HDA audio is exposed by the platform firmware to the kernel) and
makes it possible to force the kernel to return "5" as the supported
ACPI revision via the "acpi_rev_override" command line switch.
the supported ACPI revision which makes it expose system configuration
information in a special way.
For example, based on what ACPI exports as the supported revision,
Dell XPS 13 (2015) configures its audio device to either work in HDA
mode or in I2S mode, where the former is supposed to be used on Linux
until the latter is fully supported (in the kernel as well as in user
space).
This option enables a DMI-based quirk for the above Dell machine (so
that HDA audio is exposed by the platform firmware to the kernel) and
makes it possible to force the kernel to return "5" as the supported
ACPI revision via the "acpi_rev_override" command line switch.