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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT 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 562B6C4321D for ; Mon, 20 Aug 2018 17:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E81221570 for ; Mon, 20 Aug 2018 17:30:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E81221570 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726644AbeHTUq7 (ORCPT ); Mon, 20 Aug 2018 16:46:59 -0400 Received: from bmailout3.hostsharing.net ([176.9.242.62]:40127 "EHLO bmailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726077AbeHTUq7 (ORCPT ); Mon, 20 Aug 2018 16:46:59 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (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 bmailout3.hostsharing.net (Postfix) with ESMTPS id 9CD01100DA1A6; Mon, 20 Aug 2018 19:22:13 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 4EEF5240DDC; Mon, 20 Aug 2018 19:22:13 +0200 (CEST) Date: Mon, 20 Aug 2018 19:22:13 +0200 From: Lukas Wunner To: Sinan Kaya Cc: linux-pci@vger.kernel.org, Bjorn Helgaas , Mika Westerberg , Oza Pawandeep , Keith Busch , open list Subject: Re: [PATCH v8 1/2] PCI: pciehp: Ignore link events when there is a fatal error pending Message-ID: <20180820172213.tg4fle6ugi7lkhxx@wunner.de> References: <20180818065126.77912-1-okaya@kernel.org> <20180820092238.kvktwlovc64oa66e@wunner.de> 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 20, 2018 at 12:59:05PM -0400, Sinan Kaya wrote: > On 8/20/2018 5:22 AM, Lukas Wunner wrote: > > > + > > This differs from v7 of the patch in that*any* fatal error, not just > > a Surprise Link Down, results in pciehp waiting for the error to clear. > > > > I'm wondering if that's safe: Theoretically, the user might quickly > > swap the card in the slot during, say, a Completion Timeout Error, > > and with this patch pciehp would carry on as if nothing happened. > > Functionally both patches are identical. The v7 was still allowing > AER/DPC to handle all fatal error events except Surprise Link Down. > > Now, second patch (v8 2/2) is masking the surprise link down event > as we have talked before. Therefore, there is no need to filter > out incoming errors by reading the status register and masking the > unwanted bits. Ok, missed that. > Just to clarify something, this patch will wait for only the FATAL > error events to be handled by the error handling services only. > > Completion Timeout is a NONFATAL error event by default unless > somebody tweaks the severity bits. > > Anyhow, all FATAL errors cause one sort of link down either > initiated by software (AER) or hardware (DPC). > Therefore, hotplug driver will observe a link down event and > AER/DPC needs to handle the event as usual. Thanks for the clarification. Lukas