From patchwork Mon Apr 2 16:21:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 10320035 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B5FAB60247 for ; Mon, 2 Apr 2018 16:19:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A783720453 for ; Mon, 2 Apr 2018 16:19:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A7C1205AF; Mon, 2 Apr 2018 16:19:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 120C320453 for ; Mon, 2 Apr 2018 16:19:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752833AbeDBQT5 (ORCPT ); Mon, 2 Apr 2018 12:19:57 -0400 Received: from mga11.intel.com ([192.55.52.93]:40105 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752531AbeDBQT4 (ORCPT ); Mon, 2 Apr 2018 12:19:56 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Apr 2018 09:19:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,396,1517904000"; d="scan'208";a="40113138" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.44]) by orsmga003.jf.intel.com with ESMTP; 02 Apr 2018 09:19:56 -0700 From: Keith Busch To: Linux PCI , Bjorn Helgaas Cc: Oza Pawandeep , Sinan Kaya Subject: [PATCHv2 2/7] PCI/DPC: Fix PCI legacy interrupt acknowledgement Date: Mon, 2 Apr 2018 10:21:58 -0600 Message-Id: <20180402162203.3370-3-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180402162203.3370-1-keith.busch@intel.com> References: <20180402162203.3370-1-keith.busch@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Oza Pawandeep The DPC driver was acknowledging the DPC interrupt status in deferred work. That works for edge triggered interrupts, but causes an interrupt storm with level triggered legacy interrupts. This patch fixes that by clearing the interrupt status in interrupt handler. Signed-off-by: Oza Pawandeep [changelog] Reviewed-by: Keith Busch --- drivers/pci/pcie/pcie-dpc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c index a9be6938417f..82644245cb4d 100644 --- a/drivers/pci/pcie/pcie-dpc.c +++ b/drivers/pci/pcie/pcie-dpc.c @@ -112,7 +112,7 @@ static void dpc_work(struct work_struct *work) } pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, - PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT); + PCI_EXP_DPC_STATUS_TRIGGER); pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl); pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL, @@ -222,6 +222,9 @@ static irqreturn_t dpc_irq(int irq, void *context) if (dpc->rp_extensions && reason == 3 && ext_reason == 0) dpc_process_rp_pio_error(dpc); + pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, + PCI_EXP_DPC_STATUS_INTERRUPT); + schedule_work(&dpc->work); return IRQ_HANDLED;