From 66759a01adbfe8828dd063e32cf5ed3f46696181 Mon Sep 17 00:00:00 2001
From: Chuck Ebbert <76306.1226@compuserve.com>
Date: Mon, 12 Sep 2005 18:49:25 +0200
Subject: [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 @@ running once the system is up.
 			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 @@ static int __init check_bridge(int vendor, int device)
 	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 sis_apic_bug = -1;
  */
 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 @@ 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/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 @@ static void __init parse_cmdline_early (char ** cmdline_p)
 #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 @@ 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 869770d..351d8d6 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;
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 @@ extern unsigned int nmi_watchdog;
 #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 @@ extern unsigned int nmi_watchdog;
 #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;
-- 
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