+ * Vendor Support: 911
+ * Board: Some Intel ICHx based motherboards
+ * iTCO chipset: ICH7+
+ *
+ * Some Intel motherboards have a broken BIOS implementation: i.e.
+ * the SMI handler clear's the TIMEOUT bit in the TC01_STS register
+ * and does not reload the time. Thus the TCO watchdog does not reboot
+ * the system.
+ *
+ * These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after
+ * debugging: the SMI handler is quite simple - it tests value in
+ * TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
+ * the handler goes into an infinite loop, apparently to allow the
+ * second timeout and reboot. Otherwise it simply clears TIMEOUT bit
+ * in TCO1_STS and that's it.
+ * So the logic seems to be reversed, because it is hard to see how
+ * TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
+ * (other than a transitional effect).
+ *
+ * The only fix found to get the motherboard(s) to reboot is to put
+ * the glb_smi_en bit to 0. This is a dirty hack that bypasses the
+ * broken code by disabling Global SMI.
+ *
+ * WARNING: globally disabling SMI could possibly lead to dramatic
+ * problems, especially on laptops! I.e. various ACPI things where
+ * SMI is used for communication between OS and firmware.
+ *
+ * Don't use this fix if you don't need to!!!
+ */
+
+static void broken_bios_start(unsigned long acpibase)
+{
+ unsigned long val32;
+
+ val32 = inl(SMI_EN);
+ /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI#
+ Bit 0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
+ val32 &= 0xffffdffe;
+ outl(val32, SMI_EN);
+}
+
+static void broken_bios_stop(unsigned long acpibase)
+{
+ unsigned long val32;
+
+ val32 = inl(SMI_EN);
+ /* Bit 13: TCO_EN -> 1 = Enables TCO logic generating an SMI#
+ Bit 0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
+ val32 |= 0x00002001;
+ outl(val32, SMI_EN);
+}
+
+/*