Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752389AbbKYW50 (ORCPT ); Wed, 25 Nov 2015 17:57:26 -0500 Received: from proxima.lp0.eu ([81.2.80.65]:35184 "EHLO proxima.lp0.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751156AbbKYW5X (ORCPT ); Wed, 25 Nov 2015 17:57:23 -0500 Subject: [PATCH (v4) 8/11] watchdog: bcm63xx_wdt: Warn if the watchdog is currently running To: Guenter Roeck , linux-watchdog@vger.kernel.org References: <5650BFD6.5030700@simon.arlott.org.uk> <5650C08C.6090300@simon.arlott.org.uk> <5650E2FA.6090408@roeck-us.net> <5650E5BB.6020404@simon.arlott.org.uk> <56512937.6030903@roeck-us.net> <5651CB13.4090704@simon.arlott.org.uk> <5651CC90.7090402@simon.arlott.org.uk> <56552214.2050808@roeck-us.net> <56556E84.50202@simon.arlott.org.uk> <56563B1E.6050906@simon.arlott.org.uk> <56563C2C.60308@simon.arlott.org.uk> Cc: "devicetree@vger.kernel.org" , Ralf Baechle , Thomas Gleixner , Jason Cooper , Marc Zyngier , Kevin Cernekee , Florian Fainelli , Wim Van Sebroeck , Maxime Bizon , Linux Kernel Mailing List , linux-mips@linux-mips.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Jonas Gorski From: Simon Arlott Message-ID: <56563CC8.40002@simon.arlott.org.uk> Date: Wed, 25 Nov 2015 22:57:12 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <56563C2C.60308@simon.arlott.org.uk> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2595 Lines: 85 Warn when the device is registered if the hardware watchdog is currently running and report the remaining time left. Signed-off-by: Simon Arlott --- On 25/11/15 02:51, Guenter Roeck wrote: > This is really two logical changes, isn't it ? Patch 7 split into two patches. drivers/watchdog/bcm63xx_wdt.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c index ab4a794..2312dc2 100644 --- a/drivers/watchdog/bcm63xx_wdt.c +++ b/drivers/watchdog/bcm63xx_wdt.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -159,6 +160,8 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) struct bcm63xx_wdt_hw *hw; struct watchdog_device *wdd; struct resource *r; + u32 timeleft1, timeleft2; + unsigned int timeleft; int ret; hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL); @@ -199,7 +202,6 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) } raw_spin_lock_init(&hw->lock); - hw->running = false; wdd->parent = &pdev->dev; wdd->ops = &bcm63xx_wdt_ops; @@ -213,6 +215,23 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) watchdog_init_timeout(wdd, 0, &pdev->dev); watchdog_set_nowayout(wdd, nowayout); + /* Compare two reads of the time left value, 2 clock ticks apart */ + rmb(); + timeleft1 = __raw_readl(hw->regs + WDT_CTL_REG); + udelay(DIV_ROUND_UP(1000000, hw->clock_hz / 2)); + /* Ensure the register is read twice */ + rmb(); + timeleft2 = __raw_readl(hw->regs + WDT_CTL_REG); + + /* If the time left is changing, the watchdog is running */ + if (timeleft1 != timeleft2) { + hw->running = true; + timeleft = bcm63xx_wdt_get_timeleft(wdd); + } else { + hw->running = false; + timeleft = 0; + } + ret = watchdog_register_device(wdd); if (ret < 0) { dev_err(&pdev->dev, "failed to register watchdog device\n"); @@ -230,6 +249,8 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) dev_name(wdd->dev), hw->regs, wdd->timeout, wdd->max_timeout); + if (hw->running) + dev_alert(wdd->dev, "running, reboot in %us\n", timeleft); return 0; unregister_watchdog: -- 2.1.4 -- Simon Arlott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/