From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757467AbcILVJ3 (ORCPT ); Mon, 12 Sep 2016 17:09:29 -0400 Received: from mail.kernel.org ([198.145.29.136]:54340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757250AbcILVJY (ORCPT ); Mon, 12 Sep 2016 17:09:24 -0400 Subject: [PATCH v2 4/8] PCI: pciehp: Don't re-read Slot Status when queuing hotplug event To: Mayurkumar Patel From: Bjorn Helgaas Cc: Rajat Jain , MikaWesterberg@linux.intel.com, linux-pci@vger.kernel.org, Rafael J Wysocki , linux-kernel@vger.kernel.org, Keith Busch , Luis Antonio Tarazona-Duarte , Andy Shevchenko , mika.westerberg@linux.intel.com Date: Mon, 12 Sep 2016 16:09:20 -0500 Message-ID: <20160912210920.22258.26185.stgit@bhelgaas-glaptop2.roam.corp.google.com> In-Reply-To: <20160912210507.22258.63097.stgit@bhelgaas-glaptop2.roam.corp.google.com> References: <20160912210507.22258.63097.stgit@bhelgaas-glaptop2.roam.corp.google.com> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mayurkumar Patel Previously we read Slot Status to learn about hotplug events, then cleared the events, then re-read Slot Status to find out what happened. But Slot Status might have changed before the second read. Capture the Slot Status once before clearing the events. Also capture the Link Status if we had a link status change. [bhelgaas: changelog, split to separate patch] Signed-off-by: Mayurkumar Patel Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_hpc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 625fa6a..fe99b45 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -566,6 +566,10 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) if (!events) return IRQ_NONE; + /* Capture link status before clearing interrupts */ + if (events & PCI_EXP_SLTSTA_DLLSC) + link = pciehp_check_link_active(ctrl); + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events); ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events); @@ -598,7 +602,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) /* Check Presence Detect Changed */ if (events & PCI_EXP_SLTSTA_PDC) { - pciehp_get_adapter_status(slot, &present); + present = !!(status & PCI_EXP_SLTSTA_PDS); ctrl_info(ctrl, "Card %spresent on Slot(%s)\n", present ? "" : "not ", slot_name(slot)); pciehp_queue_interrupt_event(slot, present ? INT_PRESENCE_ON : @@ -613,7 +617,6 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) } if (events & PCI_EXP_SLTSTA_DLLSC) { - link = pciehp_check_link_active(ctrl); ctrl_info(ctrl, "slot(%s): Link %s event\n", slot_name(slot), link ? "Up" : "Down"); pciehp_queue_interrupt_event(slot, link ? INT_LINK_UP :