There is a cooldown period after watchdog timer setup, and also after each watchdog ping. If a ping is issued too early, the watchdog triggers the watchdog error condition and causes a system reset.
The 256 ms period length is a best guess based on the same value being used for the DA9053 predecessor PMIC and experiments that have shown 200 ms are not enough to avoid the error. Signed-off-by: Philipp Zabel <[email protected]> --- drivers/watchdog/da9063_wdt.c | 88 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 79 insertions(+), 9 deletions(-) diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c index e2fe2eb..b2e9201 100644 --- a/drivers/watchdog/da9063_wdt.c +++ b/drivers/watchdog/da9063_wdt.c @@ -35,11 +35,15 @@ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] #define DA9063_WDG_TIMEOUT wdt_timeout[3] +#define DA9063_TWDMIN 256 struct da9063_watchdog { struct da9063 *da9063; struct watchdog_device wdtdev; struct notifier_block restart_handler; + struct delayed_work ping_work; + struct mutex mutex; + bool defer_ping; }; static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) @@ -54,10 +58,23 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) return DA9063_TWDSCALE_MAX; } -static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) +static int _da9063_wdt_set_timeout(struct da9063_watchdog *wdt, + unsigned int regval) { - return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, - DA9063_TWDSCALE_MASK, regval); + struct da9063 *da9063 = wdt->da9063; + int ret; + + mutex_lock(&wdt->mutex); + + ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, + DA9063_TWDSCALE_MASK, regval); + + wdt->defer_ping = false; + schedule_delayed_work(&wdt->ping_work, msecs_to_jiffies(DA9063_TWDMIN)); + + mutex_unlock(&wdt->mutex); + + return ret; } static int da9063_wdt_start(struct watchdog_device *wdd) @@ -67,12 +84,16 @@ static int da9063_wdt_start(struct watchdog_device *wdd) int ret; selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); - ret = _da9063_wdt_set_timeout(wdt->da9063, selector); - if (ret) + ret = _da9063_wdt_set_timeout(wdt, selector); + if (ret) { dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", ret); + return ret; + } - return ret; + wdd->timeout = wdt_timeout[selector]; + + return 0; } static int da9063_wdt_stop(struct watchdog_device *wdd) @@ -80,6 +101,8 @@ static int da9063_wdt_stop(struct watchdog_device *wdd) struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; + cancel_delayed_work_sync(&wdt->ping_work); + ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); if (ret) @@ -89,9 +112,8 @@ static int da9063_wdt_stop(struct watchdog_device *wdd) return ret; } -static int da9063_wdt_ping(struct watchdog_device *wdd) +static int da9063_wdt_issue_ping(struct da9063_watchdog *wdt) { - struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, @@ -100,9 +122,45 @@ static int da9063_wdt_ping(struct watchdog_device *wdd) dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", ret); + wdt->defer_ping = false; + schedule_delayed_work(&wdt->ping_work, msecs_to_jiffies(DA9063_TWDMIN)); + return ret; } +static int da9063_wdt_ping(struct watchdog_device *wdd) +{ + struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); + int ret = 0; + + mutex_lock(&wdt->mutex); + + if (delayed_work_pending(&wdt->ping_work)) { + wdt->defer_ping = true; + + goto out; + } + + da9063_wdt_issue_ping(wdt); +out: + mutex_unlock(&wdt->mutex); + + return ret; +} + +static void da9063_wdt_ping_work(struct work_struct *work) +{ + struct da9063_watchdog *wdt = container_of(to_delayed_work(work), + struct da9063_watchdog, ping_work); + + mutex_lock(&wdt->mutex); + + if (wdt->defer_ping) + da9063_wdt_issue_ping(wdt); + + mutex_unlock(&wdt->mutex); +} + static int da9063_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { @@ -111,7 +169,7 @@ static int da9063_wdt_set_timeout(struct watchdog_device *wdd, int ret; selector = da9063_wdt_timeout_to_sel(timeout); - ret = _da9063_wdt_set_timeout(wdt->da9063, selector); + ret = _da9063_wdt_set_timeout(wdt, selector); if (ret) dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", ret); @@ -178,6 +236,9 @@ static int da9063_wdt_probe(struct platform_device *pdev) wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + INIT_DELAYED_WORK(&wdt->ping_work, da9063_wdt_ping_work); + mutex_init(&wdt->mutex); + watchdog_set_drvdata(&wdt->wdtdev, wdt); dev_set_drvdata(&pdev->dev, wdt); @@ -202,13 +263,22 @@ static int da9063_wdt_remove(struct platform_device *pdev) unregister_restart_handler(&wdt->restart_handler); watchdog_unregister_device(&wdt->wdtdev); + cancel_delayed_work_sync(&wdt->ping_work); return 0; } +static void da9063_wdt_shutdown(struct platform_device *pdev) +{ + struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); + + cancel_delayed_work_sync(&wdt->ping_work); +} + static struct platform_driver da9063_wdt_driver = { .probe = da9063_wdt_probe, .remove = da9063_wdt_remove, + .shutdown = da9063_wdt_shutdown, .driver = { .name = DA9063_DRVNAME_WATCHDOG, }, -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
