diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
index 53e04926a7b2..190d26e2e75f 100644
--- a/drivers/watchdog/sp805_wdt.c
+++ b/drivers/watchdog/sp805_wdt.c
@@ -137,10 +137,14 @@ wdt_restart(struct watchdog_device *wdd, unsigned long mode, void *cmd)
 {
 	struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
 
+	writel_relaxed(UNLOCK, wdt->base + WDTLOCK);
 	writel_relaxed(0, wdt->base + WDTCONTROL);
 	writel_relaxed(0, wdt->base + WDTLOAD);
 	writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base + WDTCONTROL);
 
+	/* Flush posted writes. */
+	readl_relaxed(wdt->base + WDTLOCK);
+
 	return 0;
 }