8 files changed, 40 insertions, 6 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bad5987c4727..fc99075e0af4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -335,6 +335,12 @@ running once the system is up.
                         timesource is not avalible, it defaults to PIT.
                         Format: { pit | tsc | cyclone | pmtmr }
 
+        disable_8254_timer
+        enable_8254_timer
+                        [IA32/X86_64] Disable/Enable interrupt 0 timer routing
+                        over the 8254 in addition to over the IO-APIC. The
+                        kernel tries to set a sensible default.
+
         hpet=           [IA-32,HPET] option to disable HPET and use PIT.
                         Format: disable
 
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 53bb9a79e274..65656c033d70 100644
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -11,7 +11,7 @@ obj-y	:= process.o semaphore.o signal.o entry.o traps.o irq.o \
 
 obj-y                           += cpu/
 obj-y                           += timers/
-obj-$(CONFIG_ACPI)              += acpi/
+obj-y                           += acpi/
 obj-$(CONFIG_X86_BIOS_REBOOT)   += reboot.o
 obj-$(CONFIG_MCA)               += mca.o
 obj-$(CONFIG_X86_MSR)           += msr.o
diff --git a/arch/i386/kernel/acpi/Makefile b/arch/i386/kernel/acpi/Makefile
index d51c7313cae8..7e9ac99354f4 100644
--- a/arch/i386/kernel/acpi/Makefile
+++ b/arch/i386/kernel/acpi/Makefile
@@ -1,4 +1,4 @@
-obj-y                           := boot.o
+obj-$(CONFIG_ACPI)              += boot.o
 obj-$(CONFIG_X86_IO_APIC)       += earlyquirk.o
 obj-$(CONFIG_ACPI_SLEEP)        += sleep.o wakeup.o
 
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 79577f0ace98..f1a21945963d 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -1111,9 +1111,6 @@ int __init acpi_boot_table_init(void)
                 disable_acpi();
                 return error;
         }
-#ifdef __i386__
-        check_acpi_pci();
-#endif
 
         acpi_table_parse(ACPI_BOOT, acpi_parse_sbf);
 
diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c
index f1b9d2a46dab..2e3b643a4dc4 100644
--- a/arch/i386/kernel/acpi/earlyquirk.c
+++ b/arch/i386/kernel/acpi/earlyquirk.c
@@ -7,14 +7,22 @@
 #include <linux/pci.h>
 #include <asm/pci-direct.h>
 #include <asm/acpi.h>
+#include <asm/apic.h>
 
 static int __init check_bridge(int vendor, int device)
 {
+#ifdef CONFIG_ACPI
         /* According to Nvidia all timer overrides are bogus. Just ignore
            them all. */
         if (vendor == PCI_VENDOR_ID_NVIDIA) {
                 acpi_skip_timer_override = 1;
         }
+#endif
+        if (vendor == PCI_VENDOR_ID_ATI && timer_over_8254 == 1) {
+                timer_over_8254 = 0;
+                printk(KERN_INFO "ATI board detected. Disabling timer routing "
+                                "over 8254.\n");
+        }
         return 0;
 }
 
diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 235822b3f41b..39d9a5fa907e 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -51,6 +51,8 @@ static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 
 static DEFINE_SPINLOCK(ioapic_lock);
 
+int timer_over_8254 __initdata = 1;
+
 /*
  *      Is the SiS APIC rmw bug present ?
  *      -1 = don't know, 0 = no, 1 = yes
@@ -2267,7 +2269,8 @@ static inline void check_timer(void)
         apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
         init_8259A(1);
         timer_ack = 1;
-        enable_8259A_irq(0);
+        if (timer_over_8254 > 0)
+                enable_8259A_irq(0);
 
         pin1  = find_isa_irq_pin(0, mp_INT);
         apic1 = find_isa_irq_apic(0, mp_INT);
@@ -2392,6 +2395,20 @@ void __init setup_IO_APIC(void)
                 print_IO_APIC();
 }
 
+static int __init setup_disable_8254_timer(char *s)
+{
+        timer_over_8254 = -1;
+        return 1;
+}
+static int __init setup_enable_8254_timer(char *s)
+{
+        timer_over_8254 = 2;
+        return 1;
+}
+
+__setup("disable_8254_timer", setup_disable_8254_timer);
+__setup("enable_8254_timer", setup_enable_8254_timer);
+
 /*
  *      Called after all the initialization is done. If we didnt find any
  *      APIC bugs then we can allow the modify fast path
diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
index 51e513b4f72d..ab62a9f4701e 100644
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -1599,6 +1599,10 @@ void __init setup_arch(char **cmdline_p)
         if (efi_enabled)
                 efi_map_memmap();
 
+#ifdef CONFIG_X86_IO_APIC
+        check_acpi_pci();       /* Checks more than just ACPI actually */
+#endif
+
 #ifdef CONFIG_ACPI
         /*
          * Parse the ACPI tables for possible boot-time SMP configuration.
diff --git a/include/asm-i386/apic.h b/include/asm-i386/apic.h
index d30b8571573f..ff9ac8d19eb2 100644
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -137,6 +137,8 @@ void switch_APIC_timer_to_ipi(void *cpumask);
 void switch_ipi_to_APIC_timer(void *cpumask);
 #define ARCH_APICTIMER_STOPS_ON_C3      1
 
+extern int timer_over_8254;
+
 #else /* !CONFIG_X86_LOCAL_APIC */
 static inline void lapic_shutdown(void) { }