[PATCH] x86: Add acpi_user_timer_override option for Asus boards

Timer overrides are normally disabled on Nvidia board because
they are commonly wrong, except on new ones with HPET support.
Unfortunately there are quite some Asus boards around that
don't have HPET, but need a timer override.

We don't know yet how to handle this transparently,
but at least add a command line option to force the timer override
and let them boot.

Cc: len.brown@intel.com

Signed-off-by: Andi Kleen <ak@suse.de>

2 files changed, 15 insertions, 1 deletions

diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 22e4c466e5a3..d12fb97a5337 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -82,6 +82,7 @@ EXPORT_SYMBOL(acpi_strict);
 acpi_interrupt_flags acpi_sci_flags __initdata;
 int acpi_sci_override_gsi __initdata;
 int acpi_skip_timer_override __initdata;
+int acpi_use_timer_override __initdata;
 
 #ifdef CONFIG_X86_LOCAL_APIC
 static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
@@ -1300,6 +1301,13 @@ static int __init parse_acpi_skip_timer_override(char *arg)
         return 0;
 }
 early_param("acpi_skip_timer_override", parse_acpi_skip_timer_override);
+
+static int __init parse_acpi_use_timer_override(char *arg)
+{
+        acpi_use_timer_override = 1;
+        return 0;
+}
+early_param("acpi_use_timer_override", parse_acpi_use_timer_override);
 #endif /* CONFIG_X86_IO_APIC */
 
 static int __init setup_acpi_sci(char *s)
diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c
index fe799b11ac0a..c9841692bb7c 100644
--- a/arch/i386/kernel/acpi/earlyquirk.c
+++ b/arch/i386/kernel/acpi/earlyquirk.c
@@ -27,11 +27,17 @@ static int __init check_bridge(int vendor, int device)
 #ifdef CONFIG_ACPI
         /* According to Nvidia all timer overrides are bogus unless HPET
            is enabled. */
-        if (vendor == PCI_VENDOR_ID_NVIDIA) {
+        if (!acpi_use_timer_override && vendor == PCI_VENDOR_ID_NVIDIA) {
                 nvidia_hpet_detected = 0;
                 acpi_table_parse(ACPI_HPET, nvidia_hpet_check);
                 if (nvidia_hpet_detected == 0) {
                         acpi_skip_timer_override = 1;
+                          printk(KERN_INFO "Nvidia board "
+                       "detected. Ignoring ACPI "
+                       "timer override.\n");
+                printk(KERN_INFO "If you got timer trouble "
+                                 "try acpi_use_timer_override\n");
+
                 }
         }
 #endif