[PATCH] x86-64: i386/x86-64: Fix time going twice as fast problem on ATI Xpress chipsets

Original patch from Bertro Simul

This is probably still not quite correct, but seems to be
the best solution so far.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c
index f1b9d2a..087ecc6 100644
--- a/arch/i386/kernel/acpi/earlyquirk.c
+++ b/arch/i386/kernel/acpi/earlyquirk.c
@@ -15,6 +15,13 @@
 	if (vendor == PCI_VENDOR_ID_NVIDIA) {
 		acpi_skip_timer_override = 1;
 	}
+	/*
+	 * ATI IXP chipsets get double timer interrupts.
+	 * For now just do this for all ATI chipsets.
+ 	 * FIXME: this needs to be checked for the non ACPI case too.
+	 */
+	if (vendor == PCI_VENDOR_ID_ATI)
+		disable_timer_pin_1 = 1;
 	return 0;
 }
 
diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 35d3ce2..378313b 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -60,6 +60,8 @@
  */
 int nr_ioapic_registers[MAX_IO_APICS];
 
+int disable_timer_pin_1 __initdata;
+
 /*
  * Rough estimation of how many shared IRQs there are, can
  * be changed anytime.
@@ -2211,6 +2213,8 @@
 				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/i386/kernel/setup.c b/arch/i386/kernel/setup.c
index f3d8084..dc39ca6 100644
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -851,6 +851,11 @@
 #endif
 
 #ifdef CONFIG_X86_LOCAL_APIC
+		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;
+
 		/* disable IO-APIC */
 		else if (!memcmp(from, "noapic", 6))
 			disable_ioapic_setup();