The watchdog resets the system if the watchdog gets pinged to fast.
Between each watchdog ping must be a pause of at least 200ms. This
commit fixes that by rejecting two fast requests.
Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
Hi,
after the a discussion we decided to change the busy wait behaviour. Now
the driver won't wait and reject the ping-request immediately to ensure
the cool down phase.
Regards,
Marco
drivers/mfd/da9063.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/mfd/da9063.c b/drivers/mfd/da9063.c
index 4d459c7f18..b1e4116906 100644
--- a/drivers/mfd/da9063.c
+++ b/drivers/mfd/da9063.c
@@ -14,6 +14,7 @@
*/
#include <common.h>
+#include <clock.h>
#include <driver.h>
#include <gpio.h>
#include <restart.h>
@@ -33,6 +34,7 @@ struct da9063 {
struct i2c_client *client1;
struct device_d *dev;
unsigned int timeout;
+ uint64_t last_ping;
};
/* forbidden/impossible value; timeout will be set to this value initially to
@@ -237,6 +239,14 @@ static int da9063_watchdog_ping(struct da9063 *priv)
int ret;
u8 val;
+ /*
+ * The watchdog has a cool down phase of 200ms and if we ping to fast
+ * the da9062/3 resets the system. Reject those requests has a maximum
+ * failure of 10% if the watchdog timeout is set to 2.048s.
+ */
+ if ((int64_t)(priv->last_ping + 200 * MSECOND - get_time_ns()) > 0)
+ return 0;
+
dev_dbg(priv->dev, "ping\n");
/* reset watchdog timer; register is self clearing */
@@ -245,6 +255,8 @@ static int da9063_watchdog_ping(struct da9063 *priv)
if (ret < 0)
return ret;
+ priv->last_ping = get_time_ns();
+
return 0;
}
--
2.20.1
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