Linux-Watchdog Archive on lore.kernel.org
 help / color / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Christophe Roullier <christophe.roullier@st.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-watchdog@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 5.5 113/542] drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe
Date: Fri, 14 Feb 2020 10:41:45 -0500
Message-ID: <20200214154854.6746-113-sashal@kernel.org> (raw)
In-Reply-To: <20200214154854.6746-1-sashal@kernel.org>

From: Christophe Roullier <christophe.roullier@st.com>

[ Upstream commit 85fdc63fe256b595f923a69848cd99972ff446d8 ]

If the watchdog hardware is already enabled during the boot process,
when the Linux watchdog driver loads, it should start/reset the watchdog
and tell the watchdog framework. As a result, ping can be generated from
the watchdog framework (if CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED is set),
until the userspace watchdog daemon takes over control

Fixes:4332d113c66a ("watchdog: Add STM32 IWDG driver")

Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191122132246.8473-1-christophe.roullier@st.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/watchdog/stm32_iwdg.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index a3a329011a06b..25188d6bbe152 100644
--- a/drivers/watchdog/stm32_iwdg.c
+++ b/drivers/watchdog/stm32_iwdg.c
@@ -262,6 +262,24 @@ static int stm32_iwdg_probe(struct platform_device *pdev)
 	watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
 	watchdog_init_timeout(wdd, 0, dev);
 
+	/*
+	 * In case of CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED is set
+	 * (Means U-Boot/bootloaders leaves the watchdog running)
+	 * When we get here we should make a decision to prevent
+	 * any side effects before user space daemon will take care of it.
+	 * The best option, taking into consideration that there is no
+	 * way to read values back from hardware, is to enforce watchdog
+	 * being run with deterministic values.
+	 */
+	if (IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED)) {
+		ret = stm32_iwdg_start(wdd);
+		if (ret)
+			return ret;
+
+		/* Make sure the watchdog is serviced */
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+	}
+
 	ret = devm_watchdog_register_device(dev, wdd);
 	if (ret)
 		return ret;
-- 
2.20.1


       reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200214154854.6746-1-sashal@kernel.org>
2020-02-14 15:41 ` Sasha Levin [this message]
2020-02-14 15:41 ` [PATCH AUTOSEL 5.5 114/542] watchdog: qcom: Use platform_get_irq_optional() for bark irq Sasha Levin

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200214154854.6746-113-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=christophe.roullier@st.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-stm32@st-md-mailman.stormreply.com \
    --cc=linux-watchdog@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=stable@vger.kernel.org \
    --cc=wim@linux-watchdog.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Watchdog Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-watchdog/0 linux-watchdog/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-watchdog linux-watchdog/ https://lore.kernel.org/linux-watchdog \
		linux-watchdog@vger.kernel.org
	public-inbox-index linux-watchdog

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-watchdog


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git