[PATCH v3 5/5] ACPI / boot: Don't handle SCI on HW reduced platforms

[Andy Shevchenko]

As per note in 5.2.9 Fixed ACPI Description Table (FADT) chapter of ACPI
specification OSPM will 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 HW reduced platform.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 arch/x86/kernel/acpi/boot.c | 4 ++--
 drivers/acpi/bus.c          | 2 +-
 drivers/acpi/osl.c          | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 71c0feae60a4..c767efa53ee0 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -489,7 +489,7 @@ acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
 
 	acpi_table_print_madt_entry(header);
 
-	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
+	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt && !acpi_gbl_reduced_hardware) {
 		acpi_sci_ioapic_setup(intsrc->source_irq,
 				      intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
 				      (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
@@ -1184,7 +1184,7 @@ 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.
 	 */
-	if (!acpi_sci_override_gsi)
+	if (!acpi_sci_override_gsi && !acpi_gbl_reduced_hardware)
 		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0,
 				      acpi_gbl_FADT.sci_interrupt);
 
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index af74b420ec83..1f3dde3bc8f8 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1035,7 +1035,7 @@ void __init acpi_early_init(void)
 	}
 
 #ifdef CONFIG_X86
-	if (!acpi_ioapic) {
+	if (!acpi_ioapic && !acpi_gbl_reduced_hardware) {
 		/* compatible (0) means level (3) */
 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index db78d353bab1..4d84118a000b 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -553,7 +553,7 @@ acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
 	 * ACPI interrupts different from the SCI in our copy of the FADT are
 	 * not supported.
 	 */
-	if (gsi != acpi_gbl_FADT.sci_interrupt)
+	if (gsi != acpi_gbl_FADT.sci_interrupt || acpi_gbl_reduced_hardware)
 		return AE_BAD_PARAMETER;
 
 	if (acpi_irq_handler)
-- 
2.11.0