2 files changed, 18 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 961b519bda56..522944a000ad 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -44,6 +44,8 @@ int sis_apic_bug; /* not actually supported, dummy for compile */
 
 static int no_timer_check;
 
+int disable_timer_pin_1 __initdata;
+
 static DEFINE_SPINLOCK(ioapic_lock);
 
 /*
@@ -297,6 +299,15 @@ void __init check_ioapic(void)
 #endif
                                         /* RED-PEN skip them on mptables too? */
                                         return;
+                                case PCI_VENDOR_ID_ATI:
+                                        /* All timer interrupts on atiixp
+                                           are doubled. Disable one. */
+                                        if (disable_timer_pin_1 == 0) {
+                                                disable_timer_pin_1 = 1;
+                                                printk(KERN_INFO
+                "ATI board detected. Disabling timer pin 1.\n");
+                                        }
+                                        return;
                                 } 
 
                                 /* No multi-function device? */
@@ -1658,6 +1669,8 @@ static inline void check_timer(void)
                                 setup_nmi();
                                 enable_8259A_irq(0);
                         }
+                        if (disable_timer_pin_1 > 0)
+                                clear_IO_APIC_pin(0, pin1);
                         return;
                 }
                 clear_IO_APIC_pin(0, pin1);
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 869770da2933..351d8d64c2fb 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -336,6 +336,11 @@ static __init void parse_cmdline_early (char ** cmdline_p)
 #endif
 #endif
 
+                if (!memcmp(from, "disable_timer_pin_1", 19))
+                        disable_timer_pin_1 = 1;
+                if (!memcmp(from, "enable_timer_pin_1", 18))
+                        disable_timer_pin_1 = -1;
+
                 if (!memcmp(from, "nolapic", 7) ||
                     !memcmp(from, "disableapic", 11))
                         disable_apic = 1;