Commit ace8f1c5 authored by Paul Menzel's avatar Paul Menzel Committed by Rafael J. Wysocki
Browse files

ACPICA: executer/exsystem: Inform users about ACPI spec violation 

ACPICA commit 05ba545ce7859392250b18c10081db25c90ed8d7

Values greater than 100 microseconds violate the ACPI specification, so
warn users about it.

From ACPI Specification version 6.2 Errata A, 19.6.128 *Stall (Stall for
a Short Time)*:

> The implementation of Stall is OS-specific, but must not relinquish
> control of the processor. Because of this, delays longer than 100
> microseconds must use Sleep instead of Stall.

Link: https://github.com/acpica/acpica/commit/05ba545c


Signed-off-by: default avatarBob Moore <robert.moore@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: default avatarkernel test robot <lkp@intel.com>
parent 1c5d62f5

drivers/acpi/acpica/exsystem.c

+5 −0
Original line number Diff line number Diff line
@@ -137,6 +137,11 @@ acpi_status acpi_ex_system_do_stall(u32 how_long_us) 
			    "Time parameter is too large (%u)", how_long_us));

		status = AE_AML_OPERAND_VALUE;

	} else {

		if (how_long_US > 100) {

			ACPI_WARNING((AE_INFO,

				      "Time parameter %u us > 100 us violating ACPI spec, please fix the firmware.",

				      how_long_us));

		}

		acpi_os_stall(how_long_us);

	}