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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 AF464ECDE43 for ; Fri, 19 Oct 2018 15:01:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7783D2083A for ; Fri, 19 Oct 2018 15:01:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7783D2083A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com 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 S1727630AbeJSXHf (ORCPT ); Fri, 19 Oct 2018 19:07:35 -0400 Received: from mga17.intel.com ([192.55.52.151]:8316 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726664AbeJSXHe (ORCPT ); Fri, 19 Oct 2018 19:07:34 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Oct 2018 08:01:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,400,1534834800"; d="scan'208";a="100889079" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga001.jf.intel.com with ESMTP; 19 Oct 2018 08:01:04 -0700 Date: Fri, 19 Oct 2018 08:58:20 -0600 From: Keith Busch To: Bjorn Helgaas Cc: Jon Derrick , Dongdong Liu , Sinan Kaya , Oza Pawandeep , Matthew Wilcox , Lukas Wunner , Christoph Hellwig , Mika Westerberg , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] PCI/AER: Enable error reporting for all ports Message-ID: <20181019145820.GB23571@localhost.localdomain> References: <153989603841.78375.436243401553964151.stgit@bhelgaas-glaptop.roam.corp.google.com> <20181018230312.GB23301@localhost.localdomain> <20181019011135.GP5906@bhelgaas-glaptop.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181019011135.GP5906@bhelgaas-glaptop.roam.corp.google.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 18, 2018 at 08:11:35PM -0500, Bjorn Helgaas wrote: > On Thu, Oct 18, 2018 at 05:03:13PM -0600, Keith Busch wrote: > > On Thu, Oct 18, 2018 at 03:53:58PM -0500, Bjorn Helgaas wrote: > > > Change the AER service driver so it binds to *all* PCIe Ports, > > > including Switch Upstream and Downstream Ports. Enable AER error > > > reporting for all these Ports, but not for any children. > > > > I'm looking at this again and think enabling/disabling error > > reporting for ports is the responsibility of the port driver, not > > the AER service. > > That's an interesting idea. Can you expand on this a little more? > Why is it the responsibility of the port driver? > > Do you think pci_enable_pcie_error_reporting() shouldn't be part of > the AER service because it updates the Device Control register, which > is in the PCIe Capability, not the AER Capability? > > What about pci_aer_clear_device_status(), which clears Device Status, > which is also in the PCIe Capability? I was comparing how other end device driver's enable this, and they all call pci_enable_pcie_error_reporting() somewhere along their pci_driver->probe path. With that in mind, are ports special compared to end devices for this particular feature? > > The following should do the same as this patch, but without making > > AER driver handle non-root ports. The report enabling/disabling > > functions are already stubbed for '!CONFIG_PCIE_AER' and have checks > > for aer_cap and firmware first. > > If we thought we should enable error reporting *always*, regardless of > whether the AER service is enabled, this would make perfect sense to > me, and I might suggest doing it in an even more generic place like > pci_configure_device() or pci_init_capabilities(). There are unfortunately still pci_driver instances that don't implement the err_handler callbacks, and may cause problems if we enable error reporting in the device when its driver isn't capable of reacting to them. If it wasn't for that, I think it would make more sense to move this responsibility from drivers to the pci core. > But that doesn't seem like where you're headed. It seems like you > still only want error reporting enabled when CONFIG_PCIEAR=y. If > that's the case, it seems like doing it in portdrv only obfuscates the > connection with AER. When CONFIG_PCIEAER is unset, the portdrv code > *looks* like it's doing something but it's really not because of the > #ifdef magic. Right, but that's no different than every other Linux pci_driver. The component that provides the pci_driver.err_handler should be responsible for requesting to enable device error reporting, and that's provided by the port driver, not AER.