From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org ([198.145.29.96]:60818 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753310AbeAaQTK (ORCPT ); Wed, 31 Jan 2018 11:19:10 -0500 From: Oza Pawandeep To: Bjorn Helgaas , Philippe Ombredanne , Thomas Gleixner , Greg Kroah-Hartman , Kate Stewart , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dongdong Liu , Keith Busch , Wei Zhang , Sinan Kaya , Timur Tabi Cc: Oza Pawandeep Subject: [PATCH] PCI/DPC: Fix INT legacy interrupt in dpc_irq Date: Wed, 31 Jan 2018 21:48:55 +0530 Message-Id: <1517415535-21850-1-git-send-email-poza@codeaurora.org> Sender: linux-pci-owner@vger.kernel.org List-ID: Current dpc driver acknowledge the interrupt in deferred work, which works okay since LPI are edge triggered. But when RP does not have MSI support, port service driver falls back to legacy GIC SPI interrupts, and with current code we do not acknowledge the interrupt and we get dpc interrupt storm. This patch acknowledges the interrupt in interrupt handler. Signed-off-by: Oza Pawandeep diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c index 2d976a6..570b561 100644 --- a/drivers/pci/pcie/pcie-dpc.c +++ b/drivers/pci/pcie/pcie-dpc.c @@ -134,7 +134,7 @@ static void interrupt_event_handler(struct work_struct *work) } pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, - PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT); + PCI_EXP_DPC_STATUS_TRIGGER); } static void dpc_rp_pio_print_tlp_header(struct device *dev, @@ -277,6 +277,8 @@ static irqreturn_t dpc_irq(int irq, void *context) schedule_work(&dpc->work); } + pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, + PCI_EXP_DPC_STATUS_INTERRUPT); return IRQ_HANDLED; } -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc., a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.