diff options
Diffstat (limited to 'arch/x86/kernel/reboot.c')
| -rw-r--r-- | arch/x86/kernel/reboot.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index d3ce37edb54d..0c016f727695 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -6,6 +6,7 @@ #include <linux/dmi.h> #include <linux/sched.h> #include <linux/tboot.h> +#include <linux/delay.h> #include <acpi/reboot.h> #include <asm/io.h> #include <asm/apic.h> @@ -35,7 +36,7 @@ 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) @@ -477,9 +478,24 @@ void __attribute__((weak)) mach_reboot_fixups(void) { } +/* + * Windows compatible x86 hardware expects 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 + * 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(); @@ -501,6 +517,13 @@ 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); |