Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932356AbcLLJsq (ORCPT ); Mon, 12 Dec 2016 04:48:46 -0500 Received: from mail01.prevas.se ([62.95.78.3]:39723 "EHLO mail01.prevas.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932313AbcLLJsp (ORCPT ); Mon, 12 Dec 2016 04:48:45 -0500 X-IronPort-AV: E=Sophos;i="5.33,334,1477954800"; d="scan'208";a="1596324" From: Rasmus Villemoes To: Wim Van Sebroeck , Guenter Roeck , Stephen Warren , Lee Jones , Eric Anholt , Florian Fainelli , Ray Jui , Scott Branden , CC: Rasmus Villemoes , , , , Subject: [PATCH] watchdog: bcm2835_wdt: set WDOG_HW_RUNNING bit when appropriate Date: Mon, 12 Dec 2016 10:48:43 +0100 Message-ID: <1481536123-9279-1-git-send-email-rasmus.villemoes@prevas.dk> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.16.8.31] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1731 Lines: 50 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 --- 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"); -- 2.7.4