Commit 7c7bcfea authored Dec 15, 2017 by Andy Shevchenko Committed by Rafael J. Wysocki Dec 28, 2017

ACPI / x86: boot: Don't setup SCI on HW-reduced platforms

As per note in 5.2.9 Fixed ACPI Description Table (FADT) chapter of ACPI
specification, on HW-reduced platforma OSPM should ignore fields related
to the ACPI HW register interface, one of which is SCI_INT.

Follow the spec and ignore any configuration done for interrupt line
defined by SCI_INT if FADT specifies a HW-reduced platform.

HW-reduced platforms will still be able to use SCI in case it provides
an override record in MADT table.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 4565c4f6

arch/x86/kernel/acpi/boot.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1209,8 +1209,9 @@ static int __init acpi_parse_madt_ioapic_entries(void)
		/*
		* If BIOS did not supply an INT_SRC_OVR for the SCI
		* pretend we got one so we can set the SCI flags.
		* But ignore setting up SCI on hardware reduced platforms.
		*/
		if (acpi_sci_override_gsi == INVALID_ACPI_IRQ)
		if (acpi_sci_override_gsi == INVALID_ACPI_IRQ && !acpi_gbl_reduced_hardware)
		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0,
		acpi_gbl_FADT.sci_interrupt);