[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, 8 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/early-quirks.c b/arch/x86_64/kernel/early-quirks.c
index 2b1245d86258..68273bff58cc 100644
--- a/arch/x86_64/kernel/early-quirks.c
+++ b/arch/x86_64/kernel/early-quirks.c
@@ -45,7 +45,13 @@ static void nvidia_bugs(void)
         /*
          * All timer overrides on Nvidia are
          * wrong unless HPET is enabled.
+         * Unfortunately that's not true on many Asus boards.
+         * We don't know yet how to detect this automatically, but
+         * at least allow a command line override.
          */
+        if (acpi_use_timer_override)
+                return;
+
         nvidia_hpet_detected = 0;
         acpi_table_parse(ACPI_HPET, nvidia_hpet_check);
         if (nvidia_hpet_detected == 0) {
@@ -53,6 +59,8 @@ static void nvidia_bugs(void)
                 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
         /* RED-PEN skip them on mptables too? */