From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [83.223.95.100]) (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 DA260239E7D; Thu, 19 Jun 2025 16:19:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.95.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750349991; cv=none; b=qATvF6axyKRZOWlF49t04KkXeeZEv4i+pYmyYALorJ/2P5sct83hUN5yWsJs2mbxiXfbUc/CSiyqrD/dTh4NSY7dZCsUyxjIy8YQ6ThbUlFlb1sukppbjTpsXKH62K04MPn5p+aiIMFL1yI0FLUYd+d01Wirws+kP5pMgSqFZ5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750349991; c=relaxed/simple; bh=EUvMuvXUhJYrW9Y8cQdOQbSD/AS5RCELa0gsBZlGw14=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YoVFl4lVYd02i5XhyPPY++LrfueEg4gpBmPNeVRKi2c1cNaQHI3a9qHI+x/qzdCqh05zqksChKbwCtlSEqQcv/BID/75JX32KfoLsdKb6KRWPX9jZigVih5lqCLBg/K6KqwZeJYsPqprRQePj5zXzKcCxTaCdvUECNAw0iIfTFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.95.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 51B602C06674; Thu, 19 Jun 2025 18:19:41 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 3CB193A0855; Thu, 19 Jun 2025 18:19:41 +0200 (CEST) Date: Thu, 19 Jun 2025 18:19:41 +0200 From: Lukas Wunner To: Raju Rangoju Cc: bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Sanath S Subject: Re: [PATCH] PCI: pciehp: fix circular lock dependency b/w pci_rescan_remove_lock and reset_lock Message-ID: References: <20250619154610.902892-1-Raju.Rangoju@amd.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250619154610.902892-1-Raju.Rangoju@amd.com> On Thu, Jun 19, 2025 at 09:16:10PM +0530, Raju Rangoju wrote: > Resolves a circular locking dependency issue between > pci_rescan_remove_lock() and ctrl->reset_lock() in the PCI hotplug > subsystem, specifically in the pciehp_unconfigure_device() function. This seems to be a false-positive because the two stacktraces are identical but pciehp_ist() is single-threaded. There is only ever a single instance of pciehp_ist() running per hotplug port, so two instances running on separate CPUs can never happen. Previous reports of the same false-positive lockdep splat, only they refer to pciehp_configure_device() instead of pciehp_unconfigure_device(): https://lore.kernel.org/r/20231015093722.GA11283@wunner.de/ https://lore.kernel.org/r/ZzJm6QrQyT48jGuN@wunner.de/ Thanks, Lukas