From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from confino.investici.org (confino.investici.org [93.190.126.19]) (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 B826236728F; Thu, 13 Aug 2026 07:43:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.190.126.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786607030; cv=none; b=J8ww+LzFBHQVZAtO54UfoyklkRLpgZxeS4S0kssRRTfByuyx5UyeG72btsGnXc8YiE9wqgHQzXi9mLmOnfm/73w5t01H/N8WnGslq/mg1oSPLtS6jiNXoAAfggLtLooCRGsENWXMwF8hsvMZI8A8mpLTzwxaYQbhW3T1YUmJdxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786607030; c=relaxed/simple; bh=wYYOcp+X7mzUdzTfl3hBNAyGN3nOGQ9ySfFeueDy/Jo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=glIk4HG5eTtbOb29zaqotX96JqayUoaopyJnkTS14P3c/hZzLWBQVdKG9AxRWC3K4UvcOJM9HzWowFrcricTaZpL7jw9Qh6lWi26dHFOOBav4OdnUOeyfuEooFtt/o4Z4oOYUf7yDCz9wcvtogkvu8Zw9eULsreZo3jcuDp1kw8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=grrlz.net; spf=pass smtp.mailfrom=grrlz.net; dkim=pass (1024-bit key) header.d=grrlz.net header.i=@grrlz.net header.b=VWNWGmia; arc=none smtp.client-ip=93.190.126.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=grrlz.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=grrlz.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=grrlz.net header.i=@grrlz.net header.b="VWNWGmia" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=grrlz.net; s=stigmate; t=1786607025; bh=9LifHOjCDZK6bCJxMXB8vcP5n7P8CcG/fRfKFgpm28c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VWNWGmiaGkf0IB9Llfdj1Ze/66BLUQ6kfeRvV2G+4SXss+y8ff+hXo1awd4t8tXms XUWzNrnvjPzMDenUIhjttGD6R/KV5FUClfUtjfIzVVARoGqPpUxSmNePTpBqV1nKkh pTAG2IOjy4yhFkMkyFFd3gaaAdmVhKkKYIseDIgo= Received: from mx1.investici.org (unknown [127.0.0.1]) by confino.investici.org (Postfix) with UTF8SMTP id 4hLHRP3zzLz10wR; Thu, 13 Aug 2026 07:43:45 +0000 (UTC) Received: by mx1.investici.org (Postfix) id 4hLHRN6PZrz10w2; Thu, 13 Aug 2026 07:43:44 +0000 (UTC) From: Bradley Morgan To: "Rafael J . Wysocki" Cc: Thierry Reding , Daniel Leznan , Thomas Gleixner , Valentin Schneider , Rosen Penev , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] clocksource/drivers/timer-ti-dm: Unregister CPU PM notifier outside of the timer lock Date: Thu, 13 Aug 2026 07:43:42 +0000 Message-ID: <20260813074343.26460-2-include@grrlz.net> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260813074343.26460-1-include@grrlz.net> References: <20260813074343.26460-1-include@grrlz.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit omap_dm_timer_remove() calls cpu_pm_unregister_notifier() with dm_timer_lock held and interrupts disabled. Nothing sleeps in there today, but it pins the helper into a context where it can never be allowed to sleep, which is in the way of restoring the RCU grace period on the cpu_pm notifier chain. Do the list lookup under the lock and move the unregister after the unlock. Nothing can race it at that point: remove() owns the device, and once the timer is off the list nobody can reach it anymore. Signed-off-by: Bradley Morgan --- drivers/clocksource/timer-ti-dm.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c index bd06afb7d522..032e102bdd0a 100644 --- a/drivers/clocksource/timer-ti-dm.c +++ b/drivers/clocksource/timer-ti-dm.c @@ -1530,7 +1530,7 @@ static int omap_dm_timer_probe(struct platform_device *pdev) */ static void omap_dm_timer_remove(struct platform_device *pdev) { - struct dmtimer *timer; + struct dmtimer *timer, *found = NULL; unsigned long flags; int ret = -EINVAL; @@ -1538,14 +1538,17 @@ static void omap_dm_timer_remove(struct platform_device *pdev) list_for_each_entry(timer, &omap_timer_list, node) if (!strcmp(dev_name(&timer->pdev->dev), dev_name(&pdev->dev))) { - if (!(timer->capability & OMAP_TIMER_ALWON)) - cpu_pm_unregister_notifier(&timer->nb); list_del(&timer->node); + found = timer; ret = 0; break; } spin_unlock_irqrestore(&dm_timer_lock, flags); + /* Unregister outside the lock: cpu_pm_unregister_notifier() may sleep. */ + if (found && !(found->capability & OMAP_TIMER_ALWON)) + cpu_pm_unregister_notifier(&found->nb); + pm_runtime_disable(&pdev->dev); if (ret) -- 2.47.3