1 files changed, 39 insertions, 2 deletions

diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index d13858818100..f6a11b9b1f98 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -354,9 +354,27 @@ static void ati_force_hpet_resume(void)
         printk(KERN_DEBUG "Force enabled HPET at resume\n");
 }
 
+static u32 ati_ixp4x0_rev(struct pci_dev *dev)
+{
+        u32 d;
+        u8  b;
+
+        pci_read_config_byte(dev, 0xac, &b);
+        b &= ~(1<<5);
+        pci_write_config_byte(dev, 0xac, b);
+        pci_read_config_dword(dev, 0x70, &d);
+        d |= 1<<8;
+        pci_write_config_dword(dev, 0x70, d);
+        pci_read_config_dword(dev, 0x8, &d);
+        d &= 0xff;
+        dev_printk(KERN_DEBUG, &dev->dev, "SB4X0 revision 0x%x\n", d);
+        return d;
+}
+
 static void ati_force_enable_hpet(struct pci_dev *dev)
 {
-        u32 uninitialized_var(val);
+        u32 d, val;
+        u8  b;
 
         if (hpet_address || force_hpet_address)
                 return;
@@ -366,14 +384,33 @@ static void ati_force_enable_hpet(struct pci_dev *dev)
                 return;
         }
 
+        d = ati_ixp4x0_rev(dev);
+        if (d  < 0x82)
+                return;
+
+        /* base address */
         pci_write_config_dword(dev, 0x14, 0xfed00000);
         pci_read_config_dword(dev, 0x14, &val);
+
+        /* enable interrupt */
+        outb(0x72, 0xcd6); b = inb(0xcd7);
+        b |= 0x1;
+        outb(0x72, 0xcd6); outb(b, 0xcd7);
+        outb(0x72, 0xcd6); b = inb(0xcd7);
+        if (!(b & 0x1))
+                return;
+        pci_read_config_dword(dev, 0x64, &d);
+        d |= (1<<10);
+        pci_write_config_dword(dev, 0x64, d);
+        pci_read_config_dword(dev, 0x64, &d);
+        if (!(d & (1<<10)))
+                return;
+
         force_hpet_address = val;
         force_hpet_resume_type = ATI_FORCE_HPET_RESUME;
         dev_printk(KERN_DEBUG, &dev->dev, "Force enabled HPET at 0x%lx\n",
                    force_hpet_address);
         cached_dev = dev;
-        return;
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS,
                          ati_force_enable_hpet);