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=-9.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 66C82C4346E for ; Sun, 27 Sep 2020 15:27:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24E0423976 for ; Sun, 27 Sep 2020 15:27:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601220470; bh=ghI4SDPcs9ny3QAb9kTUesvhXSzM8eWaBp3CgO0sxvw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:List-ID:From; b=eRSWTZASkj/WRmLCYJlWEnoUqJW7vhOkodcG5w/1eRq+fZFrfJqyHRFX1WgV81Byx A5WKOfgj4bjA30/t5SWHYRrr0Tob1CZ+YxUjcNon+jNw6H3779hXtRzWSJXvryIG15 DiaWJBUefI7D39Kr7oT+ewNcyJUaYPYQZD5YW1zM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726309AbgI0P1t (ORCPT ); Sun, 27 Sep 2020 11:27:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:49556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726210AbgI0P1t (ORCPT ); Sun, 27 Sep 2020 11:27:49 -0400 Received: from [192.168.0.112] (75-58-59-55.lightspeed.rlghnc.sbcglobal.net [75.58.59.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4286923899; Sun, 27 Sep 2020 15:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601220468; bh=ghI4SDPcs9ny3QAb9kTUesvhXSzM8eWaBp3CgO0sxvw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=AchQ5I+dL4yGR/mAb5ygcHnme9SLZ4bE9ef77rwjRZPmxep4ETDEMk+KJrUJArJEC MrmbPvApWTD4Kfl4tMPjmJGwfsVo+uf9v4hlxrR0WKjqBs+2k2MeNa5MjGsnrWKEjw SOh1KsC42i4QuKqnDdBpBaKJZlK2W3NQ4pcfio4c= Subject: Re: [PATCH 2/5 V2] PCI: pciehp: check and wait port status out of DPC before handling DLLSC and PDC To: Ethan Zhao , bhelgaas@google.com, oohall@gmail.com, ruscur@russell.cc, lukas@wunner.de, andriy.shevchenko@linux.intel.com, stuart.w.hayes@gmail.com, mr.nuke.me@gmail.com, mika.westerberg@linux.intel.com, Keith Busch Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, pei.p.jia@intel.com, ashok.raj@linux.intel.com, sathyanarayanan.kuppuswamy@intel.com References: <20200927032829.11321-1-haifeng.zhao@intel.com> <20200927032829.11321-3-haifeng.zhao@intel.com> From: Sinan Kaya Autocrypt: addr=okaya@kernel.org; keydata= mQENBFrnOrUBCADGOL0kF21B6ogpOkuYvz6bUjO7NU99PKhXx1MfK/AzK+SFgxJF7dMluoF6 uT47bU7zb7HqACH6itTgSSiJeSoq86jYoq5s4JOyaj0/18Hf3/YBah7AOuwk6LtV3EftQIhw 9vXqCnBwP/nID6PQ685zl3vH68yzF6FVNwbDagxUz/gMiQh7scHvVCjiqkJ+qu/36JgtTYYw 8lGWRcto6gr0eTF8Wd8f81wspmUHGsFdN/xPsZPKMw6/on9oOj3AidcR3P9EdLY4qQyjvcNC V9cL9b5I/Ud9ghPwW4QkM7uhYqQDyh3SwgEFudc+/RsDuxjVlg9CFnGhS0nPXR89SaQZABEB AAG0HVNpbmFuIEtheWEgPG9rYXlhQGtlcm5lbC5vcmc+iQFOBBMBCAA4FiEEYdOlMSE+a7/c ckrQvGF4I+4LAFcFAlztcAoCGwMFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AACgkQvGF4I+4L AFfidAf/VKHInxep0Z96iYkIq42432HTZUrxNzG9IWk4HN7c3vTJKv2W+b9pgvBF1SmkyQSy 8SJ3Zd98CO6FOHA1FigFyZahVsme+T0GsS3/OF1kjrtMktoREr8t0rK0yKpCTYVdlkHadxmR Qs5xLzW1RqKlrNigKHI2yhgpMwrpzS+67F1biT41227sqFzW9urEl/jqGJXaB6GV+SRKSHN+ ubWXgE1NkmfAMeyJPKojNT7ReL6eh3BNB/Xh1vQJew+AE50EP7o36UXghoUktnx6cTkge0ZS qgxuhN33cCOU36pWQhPqVSlLTZQJVxuCmlaHbYWvye7bBOhmiuNKhOzb3FcgT7kBDQRa5zq1 AQgAyRq/7JZKOyB8wRx6fHE0nb31P75kCnL3oE+smKW/sOcIQDV3C7mZKLf472MWB1xdr4Tm eXeL/wT0QHapLn5M5wWghC80YvjjdolHnlq9QlYVtvl1ocAC28y43tKJfklhHiwMNDJfdZbw 9lQ2h+7nccFWASNUu9cqZOABLvJcgLnfdDpnSzOye09VVlKr3NHgRyRZa7me/oFJCxrJlKAl 2hllRLt0yV08o7i14+qmvxI2EKLX9zJfJ2rGWLTVe3EJBnCsQPDzAUVYSnTtqELu2AGzvDiM gatRaosnzhvvEK+kCuXuCuZlRWP7pWSHqFFuYq596RRG5hNGLbmVFZrCxQARAQABiQEfBBgB CAAJBQJa5zq1AhsMAAoJELxheCPuCwBX2UYH/2kkMC4mImvoClrmcMsNGijcZHdDlz8NFfCI gSb3NHkarnA7uAg8KJuaHUwBMk3kBhv2BGPLcmAknzBIehbZ284W7u3DT9o1Y5g+LDyx8RIi e7pnMcC+bE2IJExCVf2p3PB1tDBBdLEYJoyFz/XpdDjZ8aVls/pIyrq+mqo5LuuhWfZzPPec 9EiM2eXpJw+Rz+vKjSt1YIhg46YbdZrDM2FGrt9ve3YaM5H0lzJgq/JQPKFdbd5MB0X37Qc+ 2m/A9u9SFnOovA42DgXUyC2cSbIJdPWOK9PnzfXqF3sX9Aol2eLUmQuLpThJtq5EHu6FzJ7Y L+s0nPaNMKwv/Xhhm6Y= Message-ID: Date: Sun, 27 Sep 2020 11:27:46 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200927032829.11321-3-haifeng.zhao@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 9/26/2020 11:28 PM, Ethan Zhao wrote: > diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c > index 53433b37e181..6f271160f18d 100644 > --- a/drivers/pci/hotplug/pciehp_hpc.c > +++ b/drivers/pci/hotplug/pciehp_hpc.c > @@ -710,8 +710,10 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) > down_read(&ctrl->reset_lock); > if (events & DISABLE_SLOT) > pciehp_handle_disable_request(ctrl); > - else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) > + else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) { > + pci_wait_port_outdpc(pdev); > pciehp_handle_presence_or_link_change(ctrl, events); > + } > up_read(&ctrl->reset_lock); This looks like a hack TBH. Lukas, Keith; What is your take on this? Why is device lock not protecting this situation? Is there a lock missing in hotplug driver? Sinan