From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvlN48Sr+cdnDrT776Ik4Sxgo7LzH8Nbl8TmEFExPfLekAr/QIXHu9exyltW7aO2UD5wC62 ARC-Seal: i=1; a=rsa-sha256; t=1521042692; cv=none; d=google.com; s=arc-20160816; b=NgahDwkk+bw2LiBDZ9nYEapBTbRxx7Vnk36cS1Rjgf3iysj1qTXXsUs0RIrL91jTgz hbvF+ylPwsE0XOrbXmhjZ3sUPlXXb6yK1c+vBmHWzuPDYGe8AinEis93XwPQ0Ua0boqH 4NlaRQRXaWrws/1pJ0Lkpum1sadOKpCwrMjaW75Ns7l+GQclak02FQN0Gum/JKNL/ECK Y0G+85sa8PrN9xdjL4g5TA996515lQX/dp4SLZOtRSr8gQTmyhlzrNjjBHZLeEdJV5jX KBkUlhXp/9RvG+tacJ1a5ka3gs3eAU51CK5U3/Jl3aamzYoyW8xJbPn27f8X3XfPW2ey ipPw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:date:subject:cc:to:from:dmarc-filter:dkim-signature :dkim-signature:arc-authentication-results; bh=MWAXHAHjr/JMj1MWbzr6jXLoDMTqvFSsN9g7BrY+/zU=; b=ndWXpLH2K8xlPNHGU/gG7mvSiOFVF4GuZ4Mkev6i5i3EDbmjOuZbYJyZIMGvVqJAu0 qQdoVtdZKmHNfQiY/hBEfo/DzccmVO6O/hgxqMmBbQhpqwmqIVCGX4Y1djBVN5eDdFj9 82/KqFBhYxPXxckwAlaxxPfpv81NTw2W/Yz/o6o3nDUDaH7fGitVGkxxhrRdPhvcJU+W UR5n2MElQHD0aG1CeIhlX2gn5v393hfS4URYGkjw/98GsezmmOGp6PAYc9Yq2HSYPWz9 FusuJFpTMbIYdRMSaBksmJvclhWkD4Zj4ebXdgSL6l1Etvq4SZgm6wtK1eIn3sCgkFbm crKA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=A6/IwC0X; dkim=pass header.i=@codeaurora.org header.s=default header.b=lLg1bjgt; spf=pass (google.com: domain of poza@codeaurora.org designates 198.145.29.96 as permitted sender) smtp.mailfrom=poza@codeaurora.org Authentication-Results: mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=A6/IwC0X; dkim=pass header.i=@codeaurora.org header.s=default header.b=lLg1bjgt; spf=pass (google.com: domain of poza@codeaurora.org designates 198.145.29.96 as permitted sender) smtp.mailfrom=poza@codeaurora.org DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 076A060592 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=poza@codeaurora.org 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 v2] PCI/DPC: Fix PCI legacy interrupt acknowledgement Date: Wed, 14 Mar 2018 21:20:48 +0530 Message-Id: <1521042648-20522-1-git-send-email-poza@codeaurora.org> X-Mailer: git-send-email 1.9.1 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594928862601446730?= X-GMAIL-MSGID: =?utf-8?q?1594928862601446730?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Current DPC driver acknowledges the interrupt in deferred work, which works since MSI are edge triggered. But when MSI is disabled (e.g. pci=nomsi boot option) port service driver falls back to PCI legacy INT interrupt. With current code we do not acknowledge the interrupt back in dpc_irq() 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 38e40c6..9c05120 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; -- 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.