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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 0E9AAC43381 for ; Wed, 13 Mar 2019 23:21:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3F4A21019 for ; Wed, 13 Mar 2019 23:21:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552519275; bh=4KYB1fuOeXgs3tIm3qTCeEG5sbuyLpyDeRE1rHgjPRw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1dvYBiHCc8kDAaYMXKzDdQMQcjx5Y8xyhp4VlUBHuob4X0h2HtoKwn7weGylye+9I 6V9nd789BrWTi9qJgAxA4HZ72DH4QU4qcLTsm4EW7n0xqbc90ltLdhE14F2lu/9oZk B8sgPRtbKOusiQiYfpAkHPTiv1zE0UM+VOQA0lQs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726183AbfCMXVP (ORCPT ); Wed, 13 Mar 2019 19:21:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:57378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726078AbfCMXVO (ORCPT ); Wed, 13 Mar 2019 19:21:14 -0400 Received: from localhost (unknown [12.208.228.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1521720854; Wed, 13 Mar 2019 23:21:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552519274; bh=4KYB1fuOeXgs3tIm3qTCeEG5sbuyLpyDeRE1rHgjPRw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ipEEOeCvWq+dY98ZUS9UGgzufcRz31+wbmuTXAHdkeJPBiLkhfvg12981/rpmytfZ C8psuQSeY55Ajjx0VCDNpPU+4zYvDKwZ2VXsz5yzZN0WOPkgIB15/12EmkKKIUUsbE SoisercyhfV/8XNFo1aht9Z7ZSotfI7z6TrdKG1I= Date: Wed, 13 Mar 2019 18:21:13 -0500 From: Bjorn Helgaas To: Jesse Hathaway Cc: Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: Regression causes a hang on boot with a Comtrol PCI card Message-ID: <20190313232112.GC210027@google.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Jesse, On Wed, Mar 13, 2019 at 11:50:07AM -0500, Jesse Hathaway wrote: > Two regressions cause Linux to hang on boot when a Comtrol PCI card > is present. > > If I revert the following two commits, I can boot again and the card > operates without issue: > > 1302fcf0d03e (refs/bisect/bad) PCI: Configure *all* devices, not just > hot-added ones > 1c3c5eab1715 sched/core: Enable might_sleep() and smp_processor_id() > checks early I'm very sorry about the regression, but thank you very much for narrowing it down and reporting it! How did you narrow it down to *two* commits, and do you have to revert both of them to avoid the hang? Usually a bisection identifies a single commit, and the two you mention aren't related. > ; lspci -vs 82:00.0 > 82:00.0 Multiport serial controller: Comtrol Corporation Device 0061 > Subsystem: Comtrol Corporation Device 0061 > Flags: 66MHz, medium devsel, IRQ 35, NUMA node 1 > Memory at c8004000 (32-bit, non-prefetchable) [size=4K] > Memory at c8000000 (32-bit, non-prefetchable) [size=16K] > Capabilities: [40] Hot-plug capable > Capabilities: [48] Power Management version 2 > Kernel driver in use: rp2 > Kernel modules: rp2 > > Is it possible that the problem is that the card claims to support > Hot-plug, but does not? > > I would love to help fix this issue, please let me know what other > information would be helpful to provide. Can you collect a complete dmesg log (with a working kernel) and output of "sudo lspci -vvxxx"? You can open a bug report at https://bugzilla.kernel.org, attach the logs there, and respond here with the URL. Where does the hang happen? Is it when we configure the Comtrol card? Bjorn