From patchwork Tue Sep 26 14:17:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Westerberg X-Patchwork-Id: 818657 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=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3y1jj42LChz9t3B for ; Wed, 27 Sep 2017 00:18:00 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030477AbdIZORb (ORCPT ); Tue, 26 Sep 2017 10:17:31 -0400 Received: from mga11.intel.com ([192.55.52.93]:56468 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030457AbdIZOR1 (ORCPT ); Tue, 26 Sep 2017 10:17:27 -0400 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Sep 2017 07:17:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,441,1500966000"; d="scan'208";a="1199177807" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 26 Sep 2017 07:17:24 -0700 Received: by black.fi.intel.com (Postfix, from userid 1001) id 8A8FB4B4; Tue, 26 Sep 2017 17:17:20 +0300 (EEST) From: Mika Westerberg To: Bjorn Helgaas Cc: Ashok Raj , Keith Busch , "Rafael J . Wysocki" , Lukas Wunner , Michael Jamet , Yehezkel Bernat , Mario.Limonciello@dell.com, Mika Westerberg , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 6/7] PCI: pciehp: Do not clear Presence Detect Changed during initialization Date: Tue, 26 Sep 2017 17:17:19 +0300 Message-Id: <20170926141720.25067-7-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170926141720.25067-1-mika.westerberg@linux.intel.com> References: <20170926141720.25067-1-mika.westerberg@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org It is possible that the hotplug event has already happened before the driver is attached to a PCIe hotplug downstream port. If we just clear the status we never get the hotplug interrupt and thus the event will be missed. To make sure that does not happen, we leave Presence Detect Changed bit untouched during initialization. Then once the event is unmasked we get an interrupt and handle the hotplug event properly. Signed-off-by: Mika Westerberg --- drivers/pci/hotplug/pciehp_hpc.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 83c93f9da65a..bc1622aa7a05 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -862,11 +862,16 @@ struct controller *pcie_init(struct pcie_device *dev) if (link_cap & PCI_EXP_LNKCAP_DLLLARC) ctrl->link_active_reporting = 1; - /* Clear all remaining event bits in Slot Status register */ + /* + * Clear all remaining event bits in Slot Status register except + * Presence Detect Changed. We want to make sure possible + * hotplug event is triggered when the interrupt is unmasked so + * that we don't lose that event. + */ pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | - PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | - PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); + PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_CC | + PCI_EXP_SLTSTA_DLLSC); ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c LLActRep%c\n", (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,