[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/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index db2603c..7086f0a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -164,6 +164,15 @@
 			over-ride platform specific driver.
 			See also Documentation/acpi-hotkey.txt.
 
+	enable_timer_pin_1 [i386,x86-64]
+			Enable PIN 1 of APIC timer
+			Can be useful to work around chipset bugs (in particular on some ATI chipsets)
+			The kernel tries to set a reasonable default.
+
+	disable_timer_pin_1 [i386,x86-64]
+			Disable PIN 1 of APIC timer
+			Can be useful to work around chipset bugs.
+
 	ad1816=		[HW,OSS]
 			Format: <io>,<irq>,<dma>,<dma2>
 			See also Documentation/sound/oss/AD1816.
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();
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 961b519..522944a 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -44,6 +44,8 @@
 
 static int no_timer_check;
 
+int disable_timer_pin_1 __initdata;
+
 static DEFINE_SPINLOCK(ioapic_lock);
 
 /*
@@ -297,6 +299,15 @@
 #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 @@
 				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 869770d..351d8d6 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -336,6 +336,11 @@
 #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;
diff --git a/include/asm-i386/apic.h b/include/asm-i386/apic.h
index 6a1b188..8c454aa 100644
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -130,6 +130,8 @@
 #define NMI_LOCAL_APIC	2
 #define NMI_INVALID	3
 
+extern int disable_timer_pin_1;
+
 #else /* !CONFIG_X86_LOCAL_APIC */
 static inline void lapic_shutdown(void) { }
 
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index 1559d78..6c5d5ca 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -109,6 +109,8 @@
 #define NMI_LOCAL_APIC	2
 #define NMI_INVALID	3
 
+extern int disable_timer_pin_1;
+
 #endif /* CONFIG_X86_LOCAL_APIC */
 
 extern unsigned boot_cpu_id;