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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73EC0C76196 for ; Fri, 7 Apr 2023 21:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229747AbjDGVvt (ORCPT ); Fri, 7 Apr 2023 17:51:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48978 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231271AbjDGVvr (ORCPT ); Fri, 7 Apr 2023 17:51:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AC54C679; Fri, 7 Apr 2023 14:51:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C7F0A64465; Fri, 7 Apr 2023 21:51:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2AEEC433D2; Fri, 7 Apr 2023 21:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680904304; bh=KKX2qukbqARKziXpZ5Z77M5yQRvkEtvdiQIqFTYCZsU=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=TmvDC25psL77z4S32BHtlD52ALcXUQU7psLxZkr5GV0/1iiTvsnGI9O9E+ck5bgAh ktNAF0oGPXsSk0A880Ejp3W/uD9Fuq9TD3GYJkxNn2s3W2I0aWsdk3Kq4LxIqWCnNP SFV+MFsfr6DZYVwYftXClzshWRAbpW/1uS5paeq7GGJl7VcnmotJ0yvoQ38RJ0Yru2 eDrf0LizhpEHB6cZ2azrbbGPVGaKjILcGcn8lyshCvUHCrNExe2oABhOBqvraFfMPr caWL0GZdjaS3mrrGB2q4gI838qrdSBTkr7VN68Z321xRgAvPtRy+1DbJZ5QIDJkdUo xTC6ZbmhlnI/Q== Date: Fri, 7 Apr 2023 16:51:42 -0500 From: Bjorn Helgaas To: Kuppuswamy Sathyanarayanan Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Jonathan Cameron , "Natu, Mahesh" Subject: Re: [PATCH v2] PCI/EDR: Clear PCIe Device Status errors after EDR error recovery Message-ID: <20230407215142.GA3825302@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230315235449.1279209-1-sathyanarayanan.kuppuswamy@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org [+cc Jonathan, Mahesh] On Wed, Mar 15, 2023 at 04:54:49PM -0700, Kuppuswamy Sathyanarayanan wrote: > Commit 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if > OS owns AER") adds support to clear error status in the Device Status > Register(DEVSTA) only if OS owns the AER support. But this change > breaks the requirement of the EDR feature which requires OS to cleanup > the error registers even if firmware owns the control of AER support. > > More details about this requirement can be found in PCIe Firmware > specification v3.3, Table 4-6 Interpretation of the _OSC Control Field. > If the OS supports the Error Disconnect Recover (EDR) feature and > firmware sends the EDR event, then during the EDR recovery window, OS > is responsible for the device error recovery and holds the ownership of > the following error registers. > > • Device Status Register > • Uncorrectable Error Status Register > • Correctable Error Status Register > • Root Error Status Register > • RP PIO Status Register > > So call pcie_clear_device_status() in edr_handle_event() if the error > recovery is successful. > > Reported-by: Tsaur Erwin > Signed-off-by: Kuppuswamy Sathyanarayanan Sorry I spent so much time on this, but I finally applied it to pci/aer for v6.4. I added the "Fixes: 068c29a248b6" line. It's not that 068c29a248b6 is a bug, just that EDR relied on behavior that 068c29a248b6 legitimately removed, so this patch should go where 068c29a248b6 goes. I wordsmithed the commit log to add hints about things I stumbled over. I'll post a follow-up patch to add a couple comments there, too. Thanks for your patience in educating me through all this. > --- > > Changes since v1: > * Rebased on top of v6.3-rc1. > * Fixed a typo in pcie_clear_device_status(). > > drivers/pci/pcie/edr.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c > index a6b9b479b97a..87734e4c3c20 100644 > --- a/drivers/pci/pcie/edr.c > +++ b/drivers/pci/pcie/edr.c > @@ -193,6 +193,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data) > */ > if (estate == PCI_ERS_RESULT_RECOVERED) { > pci_dbg(edev, "DPC port successfully recovered\n"); > + pcie_clear_device_status(edev); > acpi_send_edr_status(pdev, edev, EDR_OST_SUCCESS); > } else { > pci_dbg(edev, "DPC port recovery failed\n"); > -- > 2.34.1 >