-From 2ff030d44672d745c5327b72463af43f5103e99b Mon Sep 17 00:00:00 2001
-From: Gabor Juhos <juhosg@openwrt.org>
-Date: Tue, 25 Mar 2014 17:07:46 +0100
-Subject: [PATCH] watchdog: ath79-wdt: avoid spurious restarts on AR934x
-
-On some AR934x based systems, where the frequency of
-the AHB bus is relatively high, the built-in watchdog
-causes a spurious restart when it gets enabled.
-
-The possible cause of these restarts is that the timeout
-value written into the TIMER register does not reaches
-the hardware in time.
-
-Add an explicit delay into the ath79_wdt_enable function
-to avoid the spurious restarts.
-
-Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
-Cc: <stable@vger.kernel.org>
----
- drivers/watchdog/ath79_wdt.c | 10 ++++++++++
- 1 file changed, 10 insertions(+)
-
---- a/drivers/watchdog/ath79_wdt.c
-+++ b/drivers/watchdog/ath79_wdt.c
-@@ -20,6 +20,7 @@
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
- #include <linux/bitops.h>
-+#include <linux/delay.h>
- #include <linux/errno.h>
- #include <linux/fs.h>
- #include <linux/init.h>
-@@ -91,6 +92,15 @@ static inline void ath79_wdt_keepalive(v
- static inline void ath79_wdt_enable(void)
- {
- ath79_wdt_keepalive();
-+
-+ /*
-+ * Updating the TIMER register requires a few microseconds
-+ * on the AR934x SoCs at least. Use a small delay to ensure
-+ * that the TIMER register is updated within the hardware
-+ * before enabling the watchdog.
-+ */
-+ udelay(2);
-+
- ath79_wdt_wr(WDOG_REG_CTRL, WDOG_CTRL_ACTION_FCR);
- /* flush write */
- ath79_wdt_rr(WDOG_REG_CTRL);