kernel/acpi_reboot.patch

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Improve our reboot handling for compatibility with Windows. Upstream in .38?
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index c495aa8..c770e66 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -34,7 +34,7 @@ EXPORT_SYMBOL(pm_power_off);
static const struct desc_ptr no_idt = {};
static int reboot_mode;
-enum reboot_type reboot_type = BOOT_KBD;
+enum reboot_type reboot_type = BOOT_ACPI;
int reboot_force;
#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
@@ -538,9 +538,23 @@ void __attribute__((weak)) mach_reboot_fixups(void)
{
}
+/*
+ * Windows does the following on reboot:
+ * 1) If the FADT has the ACPI reboot register flag set, try it
+ * 2) If still alive, write to the keyboard controller
+ * 3) If still alive, write to the ACPI reboot register again
2011-03-28 19:15:32 +00:00
+ * 4) If still alive, write to the keyboard controller again
+ *
+ * If the machine is still alive at this stage, it gives up. We default to
+ * following the same pattern, except that if we're still alive after (4) we'll
+ * try to force a triple fault and then cycle between hitting the keyboard
+ * controller and doing that
+ */
static void native_machine_emergency_restart(void)
{
int i;
+ int attempt = 0;
+ int orig_reboot_type = reboot_type;
if (reboot_emergency)
emergency_vmx_disable_all();
@@ -562,6 +576,13 @@ static void native_machine_emergency_restart(void)
outb(0xfe, 0x64); /* pulse reset low */
udelay(50);
}
+ if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
+ attempt = 1;
+ reboot_type = BOOT_ACPI;
+ } else {
+ reboot_type = BOOT_TRIPLE;
+ }
+ break;
case BOOT_TRIPLE:
load_idt(&no_idt);