x86 quirk: Fix polarity for IRQ0 pin2 override on SB800 systems

On some SB800 systems polarity for IOAPIC pin2 is wrongly
specified as low active by BIOS. This caused system hangs after
resume from S3 when HPET was used in one-shot mode on such
systems because a timer interrupt was missed (HPET signal is
high active).

For more details see:

  http://marc.info/?l=linux-kernel&m=129623757413868

Tested-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: stable@kernel.org # 37.x, 32.x
LKML-Reference: <20110224145346.GD3658@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 4 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index b3a71137983a..3e6e2d68f761 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -72,6 +72,7 @@ u8 acpi_sci_flags __initdata;
 int acpi_sci_override_gsi __initdata;
 int acpi_skip_timer_override __initdata;
 int acpi_use_timer_override __initdata;
+int acpi_fix_pin2_polarity __initdata;
 
 #ifdef CONFIG_X86_LOCAL_APIC
 static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
@@ -415,10 +416,15 @@ acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
                 return 0;
         }
 
-        if (acpi_skip_timer_override &&
-            intsrc->source_irq == 0 && intsrc->global_irq == 2) {
-                printk(PREFIX "BIOS IRQ0 pin2 override ignored.\n");
-                return 0;
+        if (intsrc->source_irq == 0 && intsrc->global_irq == 2) {
+                if (acpi_skip_timer_override) {
+                        printk(PREFIX "BIOS IRQ0 pin2 override ignored.\n");
+                        return 0;
+                }
+                if (acpi_fix_pin2_polarity && (intsrc->inti_flags & ACPI_MADT_POLARITY_MASK)) {
+                        intsrc->inti_flags &= ~ACPI_MADT_POLARITY_MASK;
+                        printk(PREFIX "BIOS IRQ0 pin2 override: forcing polarity to high active.\n");
+                }
         }
 
         mp_override_legacy_irq(intsrc->source_irq,