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, 7 insertions, 9 deletions

diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index 76b8cd953dee..9efbdcc56425 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -143,15 +143,10 @@ static void __init ati_bugs(int num, int slot, int func)
 
 static u32 __init ati_sbx00_rev(int num, int slot, int func)
 {
-        u32 old, d;
+        u32 d;
 
-        d = read_pci_config(num, slot, func, 0x70);
-        old = d;
-        d &= ~(1<<8);
-        write_pci_config(num, slot, func, 0x70, d);
         d = read_pci_config(num, slot, func, 0x8);
         d &= 0xff;
-        write_pci_config(num, slot, func, 0x70, old);
 
         return d;
 }
@@ -160,13 +155,16 @@ static void __init ati_bugs_contd(int num, int slot, int func)
 {
         u32 d, rev;
 
-        if (acpi_use_timer_override)
-                return;
-
         rev = ati_sbx00_rev(num, slot, func);
+        if (rev >= 0x40)
+                acpi_fix_pin2_polarity = 1;
+
         if (rev > 0x13)
                 return;
 
+        if (acpi_use_timer_override)
+                return;
+
         /* check for IRQ0 interrupt swap */
         d = read_pci_config(num, slot, func, 0x64);
         if (!(d & (1<<14)))