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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 48AA0C43461 for ; Wed, 28 Apr 2021 06:57:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 131E961154 for ; Wed, 28 Apr 2021 06:57:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234373AbhD1G5q (ORCPT ); Wed, 28 Apr 2021 02:57:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:58864 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229643AbhD1G5o (ORCPT ); Wed, 28 Apr 2021 02:57:44 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1619593019; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+Tsc59MqetNg6ashY2X2omdPgZEqSVZURb8MsEroGqQ=; b=ftjvMGNejqEHuMTmVZMGZhaGOvvbuv9KDapKN0EEL32JIcbP0tREQkmv6yhKetZdVQS5em /istegquIOtIWaa/P0/6PKQWR7iwnaxApC1VxBE49eOgdKCw5aWG3NL2Sc/I9gJ0g9bz9R PHOIsT3Fj8DezC2f/pHWpgbUwnarNKE= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1A7F1AF38; Wed, 28 Apr 2021 06:56:59 +0000 (UTC) Message-ID: <0601e45130495b152bec04eee4a50e302db4cfd2.camel@suse.com> Subject: Re: [PATCH v2 2/2] pci: Support "removable" attribute for PCI devices From: Oliver Neukum To: David Laight , "'Rafael J. Wysocki'" Cc: Rajat Jain , Greg Kroah-Hartman , Bjorn Helgaas , Alan Stern , Linux Kernel Mailing List , Linux PCI , "open list:ULTRA-WIDEBAND (UWB) SUBSYSTEM:" , Bjorn Helgaas , Rajat Jain , Jesse Barnes , Dmitry Torokhov Date: Wed, 28 Apr 2021 08:56:52 +0200 In-Reply-To: References: <20210424021631.1972022-1-rajatja@google.com> <20210424021631.1972022-2-rajatja@google.com> <79b994f2476249498797e1784f735fd7@AcuMS.aculab.com> <21c6b5002c5ad36cd7fe0bb849f5eba12a614bca.camel@suse.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, den 27.04.2021, 12:59 +0000 schrieb David Laight: > From: Oliver Neukum > > Sent: 27 April 2021 13:00 > > that is true for those options, but not for the style > > of PCI hotplug which requires you to push a button and wait > > for the blinking light. > > True, I remember some of those PCI hotplug chassis from 25 years ago. > ISTR we did get the removal events working (SVR4/Unixware) but I > don't remember the relevant chassis ever being sold. > In spite of the marketing hype I suspect it was only ever possible > to remove a completely working board and replace it with an > exactly equivalent one. > > In any case those chassis are not 'surprise removal'. > > More modern drivers are less likely to crash (and burn?) when > a PCI read returns ~0u. > But I suspect an awful lot really don't handle surprise removal > very well at all. So you are saying that these systems are so rare that it should be handled as special cases if at all? Regards Oliver