[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>

1 files changed, 7 insertions, 1 deletions

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