[PATCH] watchdog: bcm2835_wdt: set WDOG_HW_RUNNING bit when appropriate
From: Rasmus Villemoes <hidden>
Date: 2016-12-12 09:48:46
A bootloader may start the watchdog device before handing control to the kernel - in that case, we should tell the kernel about it so the watchdog framework can keep it alive until userspace opens /dev/watchdog0. Signed-off-by: Rasmus Villemoes <redacted> --- drivers/watchdog/bcm2835_wdt.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
index 4dddd82..c32c45b 100644
--- a/drivers/watchdog/bcm2835_wdt.c
+++ b/drivers/watchdog/bcm2835_wdt.c@@ -55,6 +55,15 @@ struct bcm2835_wdt { static unsigned int heartbeat; static bool nowayout = WATCHDOG_NOWAYOUT; +static bool bcm2835_wdt_is_running(struct bcm2835_wdt *wdt) +{ + uint32_t cur; + + cur = readl(wdt->base + PM_RSTC); + + return !!(cur & PM_RSTC_WRCFG_FULL_RESET); +} + static int bcm2835_wdt_start(struct watchdog_device *wdog) { struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
@@ -181,6 +190,17 @@ static int bcm2835_wdt_probe(struct platform_device *pdev) watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev); watchdog_set_nowayout(&bcm2835_wdt_wdd, nowayout); bcm2835_wdt_wdd.parent = &pdev->dev; + if (bcm2835_wdt_is_running(wdt)) { + /* + * The currently active timeout value (set by the + * bootloader) may be different from the module + * heartbeat parameter or the value in device + * tree. But we just need to set WDOG_HW_RUNNING, + * because then the framework will "immediately" ping + * the device, updating the timeout. + */ + set_bit(WDOG_HW_RUNNING, &bcm2835_wdt_wdd.status); + } err = watchdog_register_device(&bcm2835_wdt_wdd); if (err) { dev_err(dev, "Failed to register watchdog device");
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2.7.4