On 13.03.20 17:04, Rasmus Villemoes wrote:
Some watchdog devices, e.g. external gpio-triggered ones, must be reset more often than once per second, which means that the current rate-limiting logic in watchdog_reset() fails to keep the board alive.
gpio-wdt.txt in the linux source tree defines a "hw_margin_ms" property used to specifiy the maximum time allowed between resetting the device. Allow any watchdog device to specify such a property, and then use a reset period of one quarter of that. We keep the current default of resetting once every 1000ms.
Signed-off-by: Rasmus Villemoes rasmus.villemoes@prevas.dk
drivers/watchdog/wdt-uclass.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c index fb3e247c5f..436a52fd08 100644 --- a/drivers/watchdog/wdt-uclass.c +++ b/drivers/watchdog/wdt-uclass.c @@ -15,6 +15,12 @@ DECLARE_GLOBAL_DATA_PTR;
#define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000)
+/*
- Reset every 1000ms, or however often is required as indicated by a
- hw_margin_ms property.
- */
+static ulong reset_period = 1000;
- int initr_watchdog(void) { u32 timeout = WATCHDOG_TIMEOUT_SECS;
@@ -36,6 +42,8 @@ int initr_watchdog(void) if (CONFIG_IS_ENABLED(OF_CONTROL)) { timeout = dev_read_u32_default(gd->watchdog_dev, "timeout-sec", WATCHDOG_TIMEOUT_SECS);
reset_period = dev_read_u32_default(gd->watchdog_dev, "hw_margin_ms",4*reset_period)/4;
Nitpicking: checkpatch will most likely complain about missing spaces here.
}
wdt_start(gd->watchdog_dev, timeout * 1000, 0); @@ -117,7 +125,7 @@ void watchdog_reset(void) /* Do not reset the watchdog too often */ now = get_timer(0); if (time_after(now, next_reset)) {
next_reset = now + 1000; /* reset every 1000ms */
next_reset = now + reset_period;
Other than that:
Reviewed-by: Stefan Roese sr@denx.de
Thanks, Stefan