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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6351DC433DF for ; Sun, 9 Aug 2020 18:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46E502065D for ; Sun, 9 Aug 2020 18:40:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726398AbgHISkz (ORCPT ); Sun, 9 Aug 2020 14:40:55 -0400 Received: from bmailout1.hostsharing.net ([83.223.95.100]:54051 "EHLO bmailout1.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726199AbgHISkz (ORCPT ); Sun, 9 Aug 2020 14:40:55 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 3FB7630000D25; Sun, 9 Aug 2020 20:40:53 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 090DE17E55; Sun, 9 Aug 2020 20:40:52 +0200 (CEST) Date: Sun, 9 Aug 2020 20:40:52 +0200 From: Lukas Wunner To: Hans de Goede Cc: Bjorn Helgaas , linux-pci@vger.kernel.org Subject: Re: Lockdep warning in PCI-e hotplug code Message-ID: <20200809184052.evq42lngznypxi4f@wunner.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Sun, Aug 09, 2020 at 08:23:20PM +0200, Hans de Goede wrote: > [ 139.759255] ============================================ > [ 139.759257] WARNING: possible recursive locking detected > [ 139.759259] 5.8.0+ #16 Tainted: G E > [ 139.759260] -------------------------------------------- > [ 139.759261] irq/125-pciehp/143 is trying to acquire lock: > [ 139.759263] ffff95ee9f3d1f38 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_check_presence+0x23/0x80 > [ 139.759269] > but task is already holding lock: > [ 139.759270] ffff95eee497e738 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xdf/0x120 False positive, the reset_lock is per-controller and multiple instances of the lock are held concurrently because pciehp controllers are nested with Thunderbolt. This was already reported by Theodore T'so: https://lore.kernel.org/linux-pci/20190402021933.GA2966@mit.edu/ So the issue is on my radar and I have some ideas how to fix it. Let me get back to you with a solution later. In the meantime, thank you for the report. Lukas