From patchwork Fri Aug 31 21:26:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 964717 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 422C7z5sLKz9sBn for ; Sat, 1 Sep 2018 07:25:35 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727457AbeIABev (ORCPT ); Fri, 31 Aug 2018 21:34:51 -0400 Received: from mga12.intel.com ([192.55.52.136]:14103 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727416AbeIABeu (ORCPT ); Fri, 31 Aug 2018 21:34:50 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Aug 2018 14:25:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,313,1531810800"; d="scan'208";a="86663855" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.44]) by orsmga001.jf.intel.com with ESMTP; 31 Aug 2018 14:25:30 -0700 From: Keith Busch To: Linux PCI , Bjorn Helgaas Cc: Benjamin Herrenschmidt , Sinan Kaya , Thomas Tai , poza@codeaurora.org, Lukas Wunner , Keith Busch Subject: [PATCH 15/16] PCI/DPC: Wait for reset complete Date: Fri, 31 Aug 2018 15:26:38 -0600 Message-Id: <20180831212639.10196-16-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180831212639.10196-1-keith.busch@intel.com> References: <20180831212639.10196-1-keith.busch@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org DPC is only for error recovery. Since we're not removing the topology and relying on link state interrupts to re-enumerate anymore, the dpc reset handler has to implement the required reset timings and checks. Signed-off-by: Keith Busch --- drivers/pci/pcie/dpc.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index 93ce26191a2b..34bac3e2beac 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -66,32 +66,38 @@ static int dpc_wait_rp_inactive(struct dpc_dev *dpc) static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) { - struct dpc_dev *dpc; - struct pcie_device *pciedev; - struct device *devdpc; - - u16 cap; + struct device *dev = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC); + struct pcie_device *pciedev = to_pcie_device(dev); + struct dpc_dev *dpc = get_service_data(pciedev); + u16 cap = dpc->cap_pos; /* * DPC disables the Link automatically in hardware, so it has * already been reset by the time we get here. - */ - devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC); - pciedev = to_pcie_device(devdpc); - dpc = get_service_data(pciedev); - cap = dpc->cap_pos; - - /* + * * Wait until the Link is inactive, then clear DPC Trigger Status * to allow the Port to leave DPC. */ pcie_wait_for_link(pdev, false); - if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc)) return PCI_ERS_RESULT_DISCONNECT; pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_TRIGGER); + /* + * PCIe 4.0r1 6.6.1, a component must enter LTSSM Detect within 20ms, + * after which we should expect an link active if the reset was + * successful. If so, software must wait a minimum 100ms before sending + * configuration requests to devices downstream this port. + * + * If the link fails to activate, either the device was physically + * removed or the link is permanently failed. + */ + msleep(20); + if (!pcie_wait_for_link(pdev, true)) + return PCI_ERS_RESULT_DISCONNECT; + msleep(100); + if (pdev->subordinate) pdev->subordinate->error_state = pci_channel_io_normal; return PCI_ERS_RESULT_RECOVERED;