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 7FFDFC433EF for ; Mon, 21 Mar 2022 03:52:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238614AbiCUDyF (ORCPT ); Sun, 20 Mar 2022 23:54:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229695AbiCUDyC (ORCPT ); Sun, 20 Mar 2022 23:54:02 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84246AD10F; Sun, 20 Mar 2022 20:52:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647834757; x=1679370757; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=+xVB4tejKj+jXZwnepYkpDsgaZslDPFHLemDy5ezqI8=; b=Z8qSyD0mhjgEm1oB8M3MmV4RasRAYQ0hMLngK3qe4okhKVIfyaBs1WPz LXwCDmsJebXNq8NkbTACJGFlZAZccPzI+Nf6ijz3/167coC268RE4BFiG No9hAR/2Q3Wx0CZgPHYLkUF7DSi09Med2etaxEIuSbvZsL/YEGsZgknf+ IJpvAj3aF+jptWl+i9QSoikRNX6NWWLiudzTwNXtr5djcBoPzNCgDARK1 PsCqNgiWAJda63lt842Figolb1dvwN0v22dHcZ1t8qd+Ld72OfvaB6QBH c36Fu0gJ1vD0BSzEPIN+hM4lP1pVDUPN+MkzflVRESXYA+s4wtKSqGxpJ Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10292"; a="257408864" X-IronPort-AV: E=Sophos;i="5.90,197,1643702400"; d="scan'208";a="257408864" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2022 20:52:36 -0700 X-IronPort-AV: E=Sophos;i="5.90,197,1643702400"; d="scan'208";a="600348464" Received: from miahcroc-mobl.amr.corp.intel.com (HELO [10.212.144.180]) ([10.212.144.180]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2022 20:52:35 -0700 Message-ID: <9d47ee80-1f92-4b52-1080-4d8325dc4a5e@linux.intel.com> Date: Sun, 20 Mar 2022 20:52:35 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.5.0 Subject: Re: [PATCH v2 1/2] PCI/AER: Disable AER service when link is in L2/L3 ready, L2 and L3 state Content-Language: en-US To: Kai-Heng Feng Cc: bhelgaas@google.com, mika.westerberg@linux.intel.com, koba.ko@canonical.com, Russell Currey , Oliver O'Halloran , Lalithambika Krishnakumar , Lu Baolu , Joerg Roedel , linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220127025418.1989642-1-kai.heng.feng@canonical.com> <427f19c6-32f0-684e-5fdd-2e5ed192b71d@linux.intel.com> From: Sathyanarayanan Kuppuswamy In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/20/22 7:38 PM, Kai-Heng Feng wrote: > On Sun, Mar 20, 2022 at 4:38 AM Sathyanarayanan Kuppuswamy > wrote: >> >> >> >> On 1/26/22 6:54 PM, Kai-Heng Feng wrote: >>> Commit 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in >>> hint") enables ACS, and some platforms lose its NVMe after resume from >> >> Why enabling ACS makes platform lose NVMe? Can you add more details >> about the problem? > > I don't have a hardware analyzer, so the only detail I can provide is > the symptom. > I believe the affected system was sent Intel, and there wasn't any > feedback since then. Since your commit log refers to ACS, I think first we need to understand following points. 1. Why we get ACSViol during S3 resume. Is this just a noise? 2. Why AER recovery fails? 3. Is this common for all platforms, or only happens in your test platform? If you are not clear about above points, I think you can submit this patch as adding suspend/resume support to AER/DPC driver and not include the issue about ACS. From your commit log, the problem is not very clear. > >> >>> S3: >>> [ 50.947816] pcieport 0000:00:1b.0: DPC: containment event, status:0x1f01 source:0x0000 >>> [ 50.947817] pcieport 0000:00:1b.0: DPC: unmasked uncorrectable error detected >>> [ 50.947829] pcieport 0000:00:1b.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Receiver ID) >>> [ 50.947830] pcieport 0000:00:1b.0: device [8086:06ac] error status/mask=00200000/00010000 >>> [ 50.947831] pcieport 0000:00:1b.0: [21] ACSViol (First) >>> [ 50.947841] pcieport 0000:00:1b.0: AER: broadcast error_detected message >>> [ 50.947843] nvme nvme0: frozen state error detected, reset controller >>> >>> It happens right after ACS gets enabled during resume. >>> >>> There's another case, when Thunderbolt reaches D3cold: >>> [ 30.100211] pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: 0000:00:1d.0 >>> [ 30.100251] pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID) >>> [ 30.100256] pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000 >>> [ 30.100262] pcieport 0000:00:1d.0: [20] UnsupReq (First) >>> [ 30.100267] pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000 >>> [ 30.100372] thunderbolt 0000:0a:00.0: AER: can't recover (no error_detected callback) >> >> no callback message means one or more devices in the given port does not >> support error handler. How is this related to ACS? > > This case is about D3cold, not related to ACS. > And no error_detected is just part of the message. The whole AER > message is more important. > > Kai-Heng > >> >>> [ 30.100401] xhci_hcd 0000:3e:00.0: AER: can't recover (no error_detected callback) >>> [ 30.100427] pcieport 0000:00:1d.0: AER: device recovery failed >>> >>> So disable AER service to avoid the noises from turning power rails >>> on/off when the device is in low power states (D3hot and D3cold), as >>> PCIe spec "5.2 Link State Power Management" states that TLP and DLLP >>> transmission is disabled for a Link in L2/L3 Ready (D3hot), L2 (D3cold >>> with aux power) and L3 (D3cold). >>> >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209149 >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453 >>> Fixes: 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in hint") >>> Signed-off-by: Kai-Heng Feng >>> --- >>> v2: >>> - Wording change. >>> >>> drivers/pci/pcie/aer.c | 31 +++++++++++++++++++++++++------ >>> 1 file changed, 25 insertions(+), 6 deletions(-) >>> >>> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c >>> index 9fa1f97e5b270..e4e9d4a3098d7 100644 >>> --- a/drivers/pci/pcie/aer.c >>> +++ b/drivers/pci/pcie/aer.c >>> @@ -1367,6 +1367,22 @@ static int aer_probe(struct pcie_device *dev) >>> return 0; >>> } >>> >>> +static int aer_suspend(struct pcie_device *dev) >>> +{ >>> + struct aer_rpc *rpc = get_service_data(dev); >>> + >>> + aer_disable_rootport(rpc); >>> + return 0; >>> +} >>> + >>> +static int aer_resume(struct pcie_device *dev) >>> +{ >>> + struct aer_rpc *rpc = get_service_data(dev); >>> + >>> + aer_enable_rootport(rpc); >>> + return 0; >>> +} >>> + >>> /** >>> * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP >>> * @dev: pointer to Root Port, RCEC, or RCiEP >>> @@ -1433,12 +1449,15 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) >>> } >>> >>> static struct pcie_port_service_driver aerdriver = { >>> - .name = "aer", >>> - .port_type = PCIE_ANY_PORT, >>> - .service = PCIE_PORT_SERVICE_AER, >>> - >>> - .probe = aer_probe, >>> - .remove = aer_remove, >>> + .name = "aer", >>> + .port_type = PCIE_ANY_PORT, >>> + .service = PCIE_PORT_SERVICE_AER, >>> + .probe = aer_probe, >>> + .suspend = aer_suspend, >>> + .resume = aer_resume, >>> + .runtime_suspend = aer_suspend, >>> + .runtime_resume = aer_resume, >>> + .remove = aer_remove, >>> }; >>> >>> /** >> >> -- >> Sathyanarayanan Kuppuswamy >> Linux Kernel Developer -- Sathyanarayanan Kuppuswamy Linux Kernel Developer