From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFDAAC28CF6 for ; Wed, 1 Aug 2018 18:00:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79535208A4 for ; Wed, 1 Aug 2018 18:00:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79535208A4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732602AbeHATrH (ORCPT ); Wed, 1 Aug 2018 15:47:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49800 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405868AbeHATIi (ORCPT ); Wed, 1 Aug 2018 15:08:38 -0400 Received: from localhost (D57E6652.static.ziggozakelijk.nl [213.126.102.82]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id A6BBC10F2; Wed, 1 Aug 2018 17:04:09 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oza Pawandeep , Bjorn Helgaas , Keith Busch , Sasha Levin Subject: [PATCH 4.17 169/336] PCI/DPC: Clear interrupt status in interrupt handler top half Date: Wed, 1 Aug 2018 18:48:24 +0200 Message-Id: <20180801165035.579863965@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180801165028.930831994@linuxfoundation.org> References: <20180801165028.930831994@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oza Pawandeep [ Upstream commit 56abbf8ad73c89d0a4c3c84b1449ceaaabd1b8c7 ] The generic IRQ handling code ensures that an interrupt handler runs with its interrupt masked or disabled. If the interrupt is level-triggered, the interrupt handler must tell its device to stop asserting the interrupt before returning. If it doesn't, we will immediately take the interrupt again when the handler returns and the generic code unmasks the interrupt. The driver doesn't know whether its interrupt is edge- or level-triggered, so it must clear its interrupt source directly in its interrupt handler. Previously we cleared the DPC interrupt status in the bottom half, i.e., in deferred work, which can cause an interrupt storm if the DPC interrupt happens to be level-triggered, e.g., if we're using INTx instead of MSI. Clear the DPC interrupt status bit in the interrupt handler, not in the deferred work. Signed-off-by: Oza Pawandeep [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pcie/dpc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -113,7 +113,7 @@ static void dpc_work(struct work_struct } 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, @@ -223,6 +223,9 @@ static irqreturn_t dpc_irq(int irq, void 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;