OMAP4 has two watchdog timers timer 2/MPU and timer 3/IVA.

Previously the device tree only described one but now it describes both.
Do not attempt to set the global variable that points to a softc or
register a watchdog if this has already been done.

Fixes rebooting on the OMAP4 based PandaBoard-ES with a device tree from
linux 4.15-rc1.

diff --git a/sys/arch/armv7/omap/omdog.c b/sys/arch/armv7/omap/omdog.c
index 376154b..575ec08 100644 (file)
--- a/sys/arch/armv7/omap/omdog.c
+++ b/sys/arch/armv7/omap/omdog.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: omdog.c,v 1.7 2016/07/27 11:45:02 patrick Exp $       */
+/*     $OpenBSD: omdog.c,v 1.8 2017/11/27 06:29:41 jsg Exp $   */
 /*
  * Copyright (c) 2013 Federico G. Schwindt <fgsch@openbsd.org>
  * Copyright (c) 2007,2009 Dale Rahn <drahn@openbsd.org>
@@ -106,10 +106,15 @@ omdog_attach(struct device *parent, struct device *self, void *aux)
        rev = bus_space_read_4(sc->sc_iot, sc->sc_ioh, WIDR);
 
        printf(" rev %d.%d\n", rev >> 4 & 0xf, rev & 0xf);
-       omdog_sc = sc;
 
        omdog_stop(sc);
 
+       /* only register one watchdog, OMAP4 has two */
+       if (omdog_sc != NULL)
+               return;
+
+       omdog_sc = sc;
+
 #ifndef SMALL_KERNEL
        wdog_register(omdog_cb, sc);
 #endif