From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B581C2F7EFF; Thu, 11 Jun 2026 02:13:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781143994; cv=none; b=rayZI42qG/ZzSn5zxdmvPcEjIvnSV6bV0QmOqOwMvnIfeLnCie8GTTQ27SWxSkgcWMhH1rCdBDzQ8lTUDSgbCXiPa38+A8SytScCekwEX4vC9T+Dun7GcH7bWXQPUkgZ2auvsQfXHUqMfXVhpHSxjT07fgLIqjFo1khrULgyPVI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781143994; c=relaxed/simple; bh=DPOBmC4tQy6fOnUI5tKm51m8YVEIZnst/dzdPa9jhxc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uh5USZ9phJKeiqF9VNBG3Bdm14x/ylLw7p5IzHwEireJge0uxFHV7BzYQMcAwCOKX2s4cP/6otwumviQ/SGSMMfgGMWtLs09OWPI+tjfMrjkyHLtnaCRZaRjHaqKDujEXpMyspvZjeqIt0oQG5S2vX5ahN2TfeFtpcuhU+yBr30= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R6d5VmFv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R6d5VmFv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE0201F00899; Thu, 11 Jun 2026 02:13:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781143992; bh=tZh8aVX3T4lxDNr2d0shJe6MRko/3CBW0KGBOvkfXjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=R6d5VmFvA2UoPZw2znDme9WtQriBEVF0Jl2lNJ+dQSzQaWrD9mxuPsAObgIMalv1U /Mt0J20yIJLfFFPvZrV8w42+anIQW1j+SoWQB/GQVN2PkqBU2DQQ+Qn+uEP3wNMgb4 Wy437xIBA+IuY1LPbTGRRfmWic+tnP1h1dJmIg/CMqSLVsLwKSmTg4YFRwaO7/pTiy zjbrdHiSQH0m6iRJLtlCXRbIh2N89jgfktrdlintP49lbEHSZnolzxF0Z7bacwFsuE ElaoB8WBV7KHYKrDKZFpUANBzMstrbqFy5iTNfE/M4JnW/tx0dpf8bpWBtodLbw8Se Z1X59STj2oCCg== From: Tzung-Bi Shih To: Jonathan Corbet , "Rafael J. Wysocki" , Greg Kroah-Hartman , Danilo Krummrich Cc: Shuah Khan , Pavel Machek , Len Brown , tzungbi@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, driver-core@lists.linux.dev, tfiga@chromium.org, senozhatsky@chromium.org, Randy Dunlap Subject: [PATCH v4 2/2] PM: dpm_watchdog: Allow disabling DPM watchdog by default Date: Thu, 11 Jun 2026 02:12:18 +0000 Message-ID: <20260611021219.2093476-3-tzungbi@kernel.org> X-Mailer: git-send-email 2.54.0.1099.g489fc7bff1-goog In-Reply-To: <20260611021219.2093476-1-tzungbi@kernel.org> References: <20260611021219.2093476-1-tzungbi@kernel.org> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Introduce the "dpm_watchdog_enabled" module parameter to allow the DPM watchdog to be enabled or disabled at boot time and runtime. Additionally, introduce the CONFIG_DPM_WATCHDOG_ENABLED Kconfig option to set default value of the module parameter at compile time. This provides flexibility for systems that want the watchdog code compiled in but inactive by default, allowing it to be enabled only when needed. --- v4: - Rewrite the commit message to indicate the module parameter is the main change in the patch. - DPM_WATCHDOG_DEFAULT_ENABLED -> DPM_WATCHDOG_ENABLED. v3: https://lore.kernel.org/all/20260608021526.1023248-3-tzungbi@kernel.org - Add "PM" tag (was missing). - Update the format and specify dependencies in kernel-parameters.txt. - Update the help message in Kconfig to reflect that dpm_watchdog_enabled can be set at runtime as well. v2: https://lore.kernel.org/all/20260604090756.2884671-3-tzungbi@kernel.org - Use module parameter and bool for dpm_watchdog_enabled. - Use IS_ENABLED(). v1: https://lore.kernel.org/all/20260528103215.505795-1-tzungbi@kernel.org Signed-off-by: Tzung-Bi Shih --- Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ drivers/base/power/main.c | 11 +++++++++++ kernel/power/Kconfig | 10 ++++++++++ 3 files changed, 28 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1abdb31fa126..718ea16ffaff 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -49,6 +49,7 @@ PCI PCI bus support is enabled. PCIE PCI Express support is enabled. PCMCIA The PCMCIA subsystem is enabled. + PM Power Management support is enabled. PNP Plug & Play support is enabled. PPC PowerPC architecture is enabled. PPT Parallel port support is enabled. @@ -5365,6 +5366,12 @@ Kernel parameters pm_debug_messages [SUSPEND,KNL] Enable suspend/resume debug messages during boot up. + pm_sleep.dpm_watchdog_enabled= + [PM] Enable or disable the DPM watchdog. Requires + CONFIG_PM_SLEEP and CONFIG_DPM_WATCHDOG enabled. + Format: + Default value is set by CONFIG_DPM_WATCHDOG_ENABLED. + pnp.debug=1 [PNP] Enable PNP debug messages (depends on the CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index c6a3300cfb7a..f58945758868 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -535,6 +535,11 @@ module_param(dpm_watchdog_all_cpu_backtrace, bool, 0644); MODULE_PARM_DESC(dpm_watchdog_all_cpu_backtrace, "Backtrace all CPUs on DPM watchdog timeout"); +static bool __read_mostly dpm_watchdog_enabled = + IS_ENABLED(CONFIG_DPM_WATCHDOG_ENABLED); +module_param(dpm_watchdog_enabled, bool, 0644); +MODULE_PARM_DESC(dpm_watchdog_enabled, "Enable DPM watchdog"); + static unsigned int __read_mostly dpm_watchdog_timeout = CONFIG_DPM_WATCHDOG_TIMEOUT; static unsigned int __read_mostly dpm_watchdog_warning_timeout = CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT; @@ -630,6 +635,9 @@ static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev) { struct timer_list *timer = &wd->timer; + if (!dpm_watchdog_enabled) + return; + wd->dev = dev; wd->tsk = current; wd->fatal = dpm_watchdog_timeout == dpm_watchdog_warning_timeout; @@ -648,6 +656,9 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd) { struct timer_list *timer = &wd->timer; + if (!dpm_watchdog_enabled) + return; + timer_delete_sync(timer); timer_destroy_on_stack(timer); } diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 530c897311d4..508ceabc4d2e 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -268,6 +268,16 @@ config DPM_WATCHDOG captured in pstore device for inspection in subsequent boot session. +config DPM_WATCHDOG_ENABLED + bool "Enable DPM watchdog by default" + depends on DPM_WATCHDOG + default y + help + If you say Y here, the DPM watchdog will be enabled by default. + If you say N, it will be compiled in but disabled. It can be + enabled at boot time via the "pm_sleep.dpm_watchdog_enabled" + kernel parameter or at runtime via sysfs. + config DPM_WATCHDOG_TIMEOUT int "Watchdog timeout to panic in seconds" range 1 120 -- 2.54.0.1099.g489fc7bff1-goog