[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>

3 files changed, 16 insertions, 0 deletions

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();