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,URIBL_BLOCKED,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 C6EC1C43381 for ; Sat, 23 Feb 2019 06:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E4FC2084F for ; Sat, 23 Feb 2019 06:49:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725952AbfBWGt3 (ORCPT ); Sat, 23 Feb 2019 01:49:29 -0500 Received: from bmailout3.hostsharing.net ([176.9.242.62]:59047 "EHLO bmailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725773AbfBWGt3 (ORCPT ); Sat, 23 Feb 2019 01:49:29 -0500 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 9A38B100D942B; Sat, 23 Feb 2019 07:49:26 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 268591D8E5; Sat, 23 Feb 2019 07:49:26 +0100 (CET) Date: Sat, 23 Feb 2019 07:49:26 +0100 From: Lukas Wunner To: Alex_Gagniuc@Dellteam.com Cc: mr.nuke.me@gmail.com, bhelgaas@google.com, Austin.Bolen@dell.com, keith.busch@intel.com, Shyam.Iyer@dell.com, okaya@kernel.org, linux-pci@vger.kernel.org, gustavo@embeddedor.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC v2 2/4] PCI: pciehp: Do not turn off slot if presence comes up after link Message-ID: <20190223064926.mh24zzlj4xykwcjf@wunner.de> References: <20190220012031.10741-1-mr.nuke.me@gmail.com> <20190220012031.10741-3-mr.nuke.me@gmail.com> <20190221073634.snvazxlzgvjhilaz@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-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Feb 22, 2019 at 07:56:28PM +0000, Alex_Gagniuc@Dellteam.com wrote: > On 2/21/19 1:36 AM, Lukas Wunner wrote: > > On Tue, Feb 19, 2019 at 07:20:28PM -0600, Alexandru Gagniuc wrote: > >> mutex_lock(&ctrl->state_lock); > >> + present = pciehp_card_present(ctrl); > >> + link_active = pciehp_check_link_active(ctrl); > >> switch (ctrl->state) { > > > > These two assignments appear to be superfluous as you're also performing > > them in pciehp_check_link_active(). > > Not sure. Between the first check, and this check, you can have several > seconds elapse depending on whether the driver's .probe()/remove() is > invoked. Whatever you got at the beginning would be stale. If you had a > picture dictionary and looked up 'bad idea', it would have a picture of > the above code with the second check removed. I don't quite follow. You're no longer using the "present" and "link_active" variables in pciehp_handle_presence_or_link_change(), the variables are set again further down in the function and you're *also* reading PDS and DLLLA in is_delayed_presence_up_event(). So the above-quoted assignments are superfluous. Am I missing something? (Sorry, I had copy-pasted the wrong function name, I meant is_delayed_presence_up_event() above, not pciehp_check_link_active(). > I've got all the other review comments addressed in my local branch. I'm > waiting on Lord Helgass' decision on which solution is better. ^^^^^^^^^^^^ Can we keep this discussion in a neutral tone please? Thanks, Lukas