8 files changed, 47 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index db2603ceabba..7086f0a90d14 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 f1b9d2a46dab..087ecc67e9b3 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 35d3ce26a544..378313b0cce9 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 f3d808451d25..dc39ca6a7eca 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 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;
diff --git a/include/asm-i386/apic.h b/include/asm-i386/apic.h
index 6a1b1882285c..8c454aa58ac6 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 1559d78894ac..6c5d5ca8383a 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;