From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933478AbdIXUnY (ORCPT ); Sun, 24 Sep 2017 16:43:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60952 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932875AbdIXUnR (ORCPT ); Sun, 24 Sep 2017 16:43:17 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Keith Busch , Bjorn Helgaas , Mayurkumar Patel Subject: [PATCH 4.13 082/109] PCI: pciehp: Report power fault only once until we clear it Date: Sun, 24 Sep 2017 22:33:43 +0200 Message-Id: <20170924203356.396994457@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170924203353.104695385@linuxfoundation.org> References: <20170924203353.104695385@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Keith Busch commit 7612b3b28c0b900dcbcdf5e9b9747cc20a1e2455 upstream. When a power fault occurs, the power controller sets Power Fault Detected in the Slot Status register, and pciehp_isr() queues an INT_POWER_FAULT event to handle it. It also clears Power Fault Detected, but since nothing has yet changed to correct the power fault, the power controller will likely set it again immediately, which may cause an infinite loop when pcie_isr() rechecks Slot Status. Fix that by masking off Power Fault Detected from new events if the driver hasn't seen the power fault clear from the previous handling attempt. Fixes: fad214b0aa72 ("PCI: pciehp: Process all hotplug events before looking for new ones") Signed-off-by: Keith Busch [bhelgaas: changelog, pull test out and add comment] Signed-off-by: Bjorn Helgaas Cc: Mayurkumar Patel Signed-off-by: Greg Kroah-Hartman --- drivers/pci/hotplug/pciehp_hpc.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -586,6 +586,14 @@ static irqreturn_t pciehp_isr(int irq, v events = status & (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); + + /* + * If we've already reported a power fault, don't report it again + * until we've done something to handle it. + */ + if (ctrl->power_fault_detected) + events &= ~PCI_EXP_SLTSTA_PFD; + if (!events) return IRQ_NONE;