Hi Stefan,
Just noticed something when updating our internal u-boot repo
On Fri, Apr 12, 2019 at 2:00 AM Stefan Roese sr@denx.de wrote:
This patch tries to implement a generic watchdog_reset() function that can be used by all boards that want to service the watchdog device in U-Boot. This watchdog servicing is enabled via CONFIG_WATCHDOG.
Without this approach, new boards or platforms needed to implement a board specific version of this functionality, mostly copy'ing the same code over and over again into their board or platforms code base.
With this new generic function, the scattered other functions are now removed to be replaced by the generic one. The new version also enables the configuration of the watchdog timeout via the DT "timeout-sec" property (if enabled via CONFIG_OF_CONTROL).
This patch also adds a new flag to the GD flags, to flag that the watchdog is ready to use and adds the pointer to the watchdog device to the GD. This enables us to remove the global "watchdog_dev" variable, which was prone to cause problems because of its potentially very early use in watchdog_reset(), even before the BSS is cleared.
<snip>
diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c index 23b7e3360d..bbfac4f0f9 100644 --- a/drivers/watchdog/wdt-uclass.c +++ b/drivers/watchdog/wdt-uclass.c @@ -10,6 +10,8 @@ #include <dm/device-internal.h> #include <dm/lists.h>
+DECLARE_GLOBAL_DATA_PTR;
int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) { const struct wdt_ops *ops = device_get_ops(dev); @@ -63,6 +65,30 @@ int wdt_expire_now(struct udevice *dev, ulong flags) return ret; }
+#if defined(CONFIG_WATCHDOG) +/*
- Called by macro WATCHDOG_RESET. This function be called *very* early,
- so we need to make sure, that the watchdog driver is ready before using
- it in this function.
- */
+void watchdog_reset(void) +{
static ulong next_reset;ulong now;/* Exit if GD is not ready or watchdog is not initialized yet */if (!gd || !(gd->flags & GD_FLG_WDT_READY))return;/* Do not reset the watchdog too often */now = get_timer(0);if (now > next_reset) {
If the counter wraps we stop tickling the watchdog and the board will reset. On our 32-bit arm boards this is only about 72 minutes so it got noticed in production testing. The fix we had in our board code was:
+#ifndef time_after +#define time_after(a,b) \ + ((long)((b) - (a)) < 0) +#endif
@@ -202,7 +208,7 @@ void watchdog_reset(void) now = timer_get_us();
/* Do not reset the watchdog too often */ - if (now > next_reset) { + if (time_after(now, next_reset)) { wdt_reset(watchdog_dev); next_reset = now + 1000; }
I'll send a proper patch (gmail will eat the whitespace in the inline diff).
next_reset = now + 1000; /* reset every 1000ms */wdt_reset(gd->watchdog_dev);}+} +#endif
static int wdt_post_bind(struct udevice *dev) { #if defined(CONFIG_NEEDS_MANUAL_RELOC)