ichsmb: shutdown interrupts to prevent spurious interrupts after kexec

Obtained from:	Hewlett Packard Enterprise
Rebiewed by:	jhb, jhibbits

sys/dev/ichsmb/ichsmb.c

@@ -703,4 +703,15 @@ ichsmb_detach(device_t dev)
 	return 0;
 }
 
+int
+ichsmb_shutdown(device_t dev)
+{
+	const sc_p sc = device_get_softc(dev);
+
+	/* Disable interrupts */
+	bus_write_1(sc->io_res, ICH_HST_CNT, 0);
+
+	return (0);
+}
+
 DRIVER_MODULE(smbus, ichsmb, smbus_driver, 0, 0);

sys/dev/ichsmb/ichsmb_pci.c

@@ -243,6 +243,7 @@ static device_method_t ichsmb_pci_methods[] = {
         DEVMETHOD(device_probe, ichsmb_pci_probe),
         DEVMETHOD(device_attach, ichsmb_pci_attach),
         DEVMETHOD(device_detach, ichsmb_detach),
+        DEVMETHOD(device_shutdown, ichsmb_shutdown),
 
 	/* SMBus methods */
         DEVMETHOD(smbus_callback, ichsmb_callback),

sys/dev/ichsmb/ichsmb_var.h

@@ -84,6 +84,7 @@ extern void	ichsmb_release_resources(sc_p sc);
 extern int	ichsmb_probe(device_t dev);
 extern int	ichsmb_attach(device_t dev);
 extern int	ichsmb_detach(device_t dev);
+extern int	ichsmb_shutdown(device_t dev);
 
 #endif /* _DEV_ICHSMB_ICHSMB_VAR_H */