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 69E754219EB; Thu, 4 Jun 2026 09:08:55 +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=1780564136; cv=none; b=lQjXAmijYmR8mUMq8qjIIuxtI5U1t4KlS9QkmpEOWj0M+uAN4Vg6vdWljeVfo5Hxpvbf4ZjeR6ORsWfBQRp+GBThW9pioJCa/C0i9cZw+jmCBIEJmdpyMMuDcEQ2Uj67yEb3L3vjhOARIw7HPh8TPbJ9kvAc8Py0cHwMdA2LeVQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780564136; c=relaxed/simple; bh=1NKFWL2NyVxy6Y6uj2DWwKX9cpfJCoivyYZ47AVpgy8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y4ezwEhhCe5TCmx9/3DSacbSkfNVPmy+sVrduNkNL9txzPFAKsuKkYvhKssHV9Xl/kWBJWyACoKOnL8tIq1TXLmkGAFLoiraHwWoPW7ueUyxIbDQlXBjZw3RUizc9C7MrXA0+IvqDMFz/+eO5GQCzRVsfOHDgnHHghwju/iTAWw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KcLDXcjW; 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="KcLDXcjW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8DB01F00899; Thu, 4 Jun 2026 09:08:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780564135; bh=FFTwwbkj61o3Y4O9YgiQkwjXl0EBdIaAq8zyegWIOt4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KcLDXcjWGtAg2811Q+a2RAuhJG6qki9A5EQagMO5XyJG4wv5b2Iw1AsJzHgIHAHDK XE6gM248njueuhrdCZopJzfkhImR2ltMPGPxXBPvaF6FIvh5xj3loqNWC4eIcoNZmS bok0gleFi60nuvGgl5meS8v09FU0UdhSjC9HYJ2/Uz5iXZsYi4ReYUl4EysSjcyOP+ iJszwYng6Y1gRtmnk52ALJPfAU3pe8jUwJ31GyCaFHKbKQMgMzKnxc50FYdIbgQNyg OvjOqfvsuf70R+mjw02IetdUCUwGF/wC6y8yu7LNHMx36NaCpmkHZKzxCoQMMuk3+u T9bIYFTdr/Fng== 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 Subject: [PATCH v2 3/3] PM: dpm_watchdog: Add sysctl interface for DPM watchdog timeouts Date: Thu, 4 Jun 2026 09:07:55 +0000 Message-ID: <20260604090756.2884671-8-tzungbi@kernel.org> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog In-Reply-To: <20260604090756.2884671-1-tzungbi@kernel.org> References: <20260604090756.2884671-1-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 sysctl knobs to allow configuring DPM watchdog timeouts at runtime. Currently, these timeouts are fixed at compile time via CONFIG_DPM_WATCHDOG_TIMEOUT and CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT. This limits flexibility if the timeouts need to be adjusted for different testing scenarios or hardware behaviors without rebuilding the kernel. Add the following sysctl files under /proc/sys/kernel/: - dpm_watchdog_timeout_secs: The total timeout before panic. The maximum value is capped at CONFIG_DPM_WATCHDOG_TIMEOUT to prevent unreasonably large timeouts. - dpm_watchdog_warning_timeout_secs: The warning timeout. The maximum value is capped at the current dpm_watchdog_timeout_secs. Both sysctls have a minimum value of 1. Signed-off-by: Tzung-Bi Shih --- v2: - New to the series. v1: Doesn't exist. drivers/base/power/main.c | 61 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 57 insertions(+), 4 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 7822c29b7c8d..c1a4b30fafb2 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -539,6 +540,58 @@ static bool __read_mostly 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; +static const unsigned int dpm_watchdog_timeout_max = CONFIG_DPM_WATCHDOG_TIMEOUT; + +static int proc_dodpm_watchdog_timeout_secs(const struct ctl_table *table, + int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + struct ctl_table ctl = *table; + unsigned int val = dpm_watchdog_timeout; + int ret; + + ctl.data = &val; + ret = proc_douintvec_minmax(&ctl, write, buffer, lenp, ppos); + if (ret || !write) + return ret; + + if (val < dpm_watchdog_warning_timeout) + dpm_watchdog_warning_timeout = val; + dpm_watchdog_timeout = val; + + return 0; +} + +static const struct ctl_table dpm_watchdog_sysctls[] = { + { + .procname = "dpm_watchdog_timeout_secs", + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dodpm_watchdog_timeout_secs, + .extra1 = SYSCTL_ONE, + .extra2 = (void *)&dpm_watchdog_timeout_max, + }, + { + .procname = "dpm_watchdog_warning_timeout_secs", + .data = &dpm_watchdog_warning_timeout, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = SYSCTL_ONE, + .extra2 = (void *)&dpm_watchdog_timeout, + }, +}; + +static int __init dpm_watchdog_sysctl_init(void) +{ + register_sysctl_init("kernel", dpm_watchdog_sysctls); + return 0; +} +subsys_initcall(dpm_watchdog_sysctl_init); + /** * dpm_watchdog_handler - Driver suspend / resume watchdog handler. * @t: The timer that PM watchdog depends on. @@ -564,9 +617,9 @@ static void dpm_watchdog_handler(struct timer_list *t) dev_driver_string(wd->dev), dev_name(wd->dev)); } - time_left = CONFIG_DPM_WATCHDOG_TIMEOUT - CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT; + time_left = dpm_watchdog_timeout - dpm_watchdog_warning_timeout; dev_warn(wd->dev, "**** DPM device timeout after %u seconds; %u seconds until panic ****\n", - CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT, time_left); + dpm_watchdog_warning_timeout, time_left); show_stack(wd->tsk, NULL, KERN_WARNING); wd->fatal = true; @@ -587,11 +640,11 @@ static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev) wd->dev = dev; wd->tsk = current; - wd->fatal = CONFIG_DPM_WATCHDOG_TIMEOUT == CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT; + wd->fatal = dpm_watchdog_timeout == dpm_watchdog_warning_timeout; timer_setup_on_stack(timer, dpm_watchdog_handler, 0); /* use same timeout value for both suspend and resume */ - timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT; + timer->expires = jiffies + HZ * dpm_watchdog_warning_timeout; add_timer(timer); } -- 2.54.0.1032.g2f8565e1d1-goog