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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-07-03 02:06:00 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-07-03 02:06:00 +0300 |
| commit | 18d78b64fddc11eb336f01e46ad3303a3f55d039 (patch) | |
| tree | 806559410131313aa86fa78510e34f1592cbb4ad /drivers/acpi/internal.h | |
| parent | ce55d01e9b4daee5040777d023d52e6b42d3ad8f (diff) | |
| download | linux-18d78b64fddc11eb336f01e46ad3303a3f55d039.tar.xz | |
ACPI / init: Make it possible to override _REV
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).
Since ACPI 6 mandates that _REV should return "2" if ACPI 2 or later
is supported by the OS, a subsequent change will make that happen, so
make it possible to override that on systems where "5" is expected to
be returned for Linux to work correctly one them (such as the Dell
machine mentioned above).
Original-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/internal.h')
| -rw-r--r-- | drivers/acpi/internal.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index ba4a61e964be..42f304288829 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -58,6 +58,7 @@ void acpi_cmos_rtc_init(void); #else static inline void acpi_cmos_rtc_init(void) {} #endif +int acpi_rev_override_setup(char *str); extern bool acpi_force_hot_remove; |