From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1D85E9B24D for ; Tue, 24 Feb 2026 11:07:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=xNOstNU/LoXPbiPBMZ5TS+sK3wIHcDh7uayqfpO8Q1U=; b=tQcUSiYilGfylvKzSzmHvIwtTc PuCRzjpqk+VF77/XFvNZWOhIw4CkpWd6ZiprGo1gGiWP+lFhAlZJ+em583QRf3LwvtsfJx5hbMTDA 2WsByo5kk+9G0lLvIiJq1Zqn6/gKTw5qWXi3bDONF+HkuJkYa9hJCMThy4TOVJhSAIHm5i6V8i425 rPsdCR4wpc9XtuHLBR9/bp16mRBJTDCBuU0/Pyp0hChXvOJShL/Si3WSyE5Wed4sI8aWTTRLhG52U eNX4QCicVB9esjJXeOBzM711gr2TiO95wH8Mxe+3POpditR/yniU8BAvq3yZDQJUko/vg/D9XcxR2 P6CeKqSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vuqFt-00000001wGT-3eOp; Tue, 24 Feb 2026 11:07:05 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vuqFr-00000001wG9-2oNU for linux-arm-kernel@lists.infradead.org; Tue, 24 Feb 2026 11:07:04 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C35D7339; Tue, 24 Feb 2026 03:06:55 -0800 (PST) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9C3FF3F59E; Tue, 24 Feb 2026 03:07:01 -0800 (PST) Date: Tue, 24 Feb 2026 11:06:59 +0000 From: Leo Yan To: Suzuki K Poulose Cc: Mike Leach , James Clark , Alexander Shishkin , Greg Kroah-Hartman , Mathieu Poirier , Mao Jinlong , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/8] coresight: Fix device registration and unregistration Message-ID: <20260224110659.GA4184494@e132581.arm.com> References: <20260209-arm_coresight_refactor_dev_register-v4-0-62d6042f76f7@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260224_030703_750510_AB6611B4 X-CRM114-Status: UNSURE ( 8.02 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Feb 23, 2026 at 01:28:03PM +0000, Suzuki K Poulose wrote: [...] > [ 827.216924] Possible unsafe locking scenario: > [ 827.216924] > [ 827.222849] CPU0 CPU1 > [ 827.227380] ---- ---- > [ 827.231912] lock(coresight_mutex); > [ 827.235491] lock(ect_mutex); > [ 827.241073] lock(coresight_mutex); > [ 827.247176] lock(ect_mutex); > [ 827.250233] > [ 827.250233] *** DEADLOCK *** Thanks for the test, Suzuki. I have sent a refactor patch to dismiss locking chain: https://lore.kernel.org/linux-arm-kernel/20260224-arm_coresight_refactor_cti_resource_release-v1-1-ff1b2bca9176@arm.com/T/#u For recording, I enabled the following configs to reproduce the lockdep report: CONFIG_LOCKUP_DETECTOR CONFIG_PROVE_LOCKING Thanks, Leo