ssb: extif: add check for max value before setting watchdog register

Prevent the watchdog register on the extif core to be set to a too
high value.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/ssb/driver_extif.c

@@ -112,9 +112,10 @@ void ssb_extif_get_clockcontrol(struct ssb_extif *extif,
 	*m = extif_read32(extif, SSB_EXTIF_CLOCK_SB);
 }
 
-void ssb_extif_watchdog_timer_set(struct ssb_extif *extif,
-				  u32 ticks)
+void ssb_extif_watchdog_timer_set(struct ssb_extif *extif, u32 ticks)
 {
+	if (ticks > SSB_EXTIF_WATCHDOG_MAX_TIMER)
+		ticks = SSB_EXTIF_WATCHDOG_MAX_TIMER;
 	extif_write32(extif, SSB_EXTIF_WATCHDOG, ticks);
 }
 

include/linux/ssb/ssb_driver_extif.h

@@ -152,6 +152,7 @@
 /* watchdog */
 #define SSB_EXTIF_WATCHDOG_CLK		48000000	/* Hz */
 
+#define SSB_EXTIF_WATCHDOG_MAX_TIMER	((1 << 28) - 1)
 
 
 #ifdef CONFIG_SSB_DRIVER_EXTIF